Examples with solutions for Factorization - Common Factor: Solving the problem

Exercise #1

x1009x99=0 x^{100}-9x^{99}=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

x1009x99=0 x^{100}-9x^{99}=0

First, note that in the left side we can factor out a common factor from the terms, the largest common factor for the numbers and letters in this case is x99 x^{99} because the power of 99 is the lowest power in the equation and therefore is included both in the term with power of 100 and in the term with power of 99. Any power higher than this is not included in the term with the lowest power of 99, and therefore this is the term with the highest power that can be factored out as a common factor from all letter terms,

Let's continue and perform the factoring:

x1009x99=0x99(x9)=0 x^{100}-9x^{99}=0 \\ \downarrow\\ x^{99}(x-9)=0

Let's continue and address the fact that on the left side of the equation we received in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get a result of 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

Meaning:

x99=0/99x=0 x^{99}=0 \hspace{8pt}\text{/}\sqrt[99]{\hspace{6pt}}\\ \boxed{x=0}

In solving the equation above, we extracted a 99th root from both sides of the equation.

(In this case, extracting an odd root from the right side of the equation yielded one possibility)

Or:

x9=0x=9 x-9=0 \\ \boxed{x=9}

Let's summarize the solution of the equation:

x1009x99=0x99(x9)=0x99=0x=0x9=0x=9x=0,9 x^{100}-9x^{99}=0 \\ \downarrow\\ x^{99}(x-9)=0 \\ \downarrow\\ x^{99}=0 \rightarrow\boxed{ x=0}\\ x-9=0\rightarrow \boxed{x=9}\\ \downarrow\\ \boxed{x=0,9}

Therefore, the correct answer is answer C.

Answer

x=0,9 x=0,9

Exercise #2

x75x6=0 x^7-5x^6=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

x75x6=0 x^7-5x^6=0

First let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and letters in this case is x6 x^6 since the sixth power is the lowest power in the equation and therefore is included both in the term with the seventh power and in the term with the sixth power, any power higher than this is not included in the term with the sixth power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms in the expression, so we'll continue and perform the factoring:

x75x6=0x6(x5)=0 x^7-5x^6=0 \\ \downarrow\\ x^6(x-5)=0

Let's continue and address the fact that in the left side of the equation we got in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

meaning:

x6=0/6x=±0x=0 x^6=0 \hspace{8pt}\text{/}\sqrt[6]{\hspace{6pt}}\\ x=\pm0\\ \boxed{x=0}

(in this case taking the even root of the right side of the equation will yield two possibilities - positive and negative, however since we're dealing with zero, we get only one solution)

or:

x5=0x=5 x-5=0\\ \downarrow\\ \boxed{x=5}

Let's summarize the solution of the equation:

x75x6=0x6(x5)=0x6=0x=0x5=0x=5x=0,5 x^7-5x^6=0 \\ \downarrow\\ x^6(x-5)=0 \\ \downarrow\\ x^6=0 \rightarrow\boxed{ x=0}\\ x-5=0 \rightarrow \boxed{x=5}\\ \downarrow\\ \boxed{x=0,5}

Therefore the correct answer is answer A.

Answer

x=0,5 x=0,5

Exercise #3

15x430x3=0 15x^4-30x^3=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

15x430x3=0 15x^4-30x^3=0

First, let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and variables in this case is 15x3 15x^3 since the third power is the lowest power in the equation and therefore is included in both the term with the fourth power and the term with the third power, any power higher than this is not included in the term with the third power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms for the variables,

For the numbers, note that 30 is a multiple of 15, therefore 15 is the largest common factor for the numbers for both terms in the expression,

Let's continue and perform the factoring:

15x430x3=015x3(x2)=0 15x^4-30x^3=0 \\ \downarrow\\ 15x^3(x-2)=0

Let's continue and address the fact that in the left side of the equation we got in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 as a result of multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

Meaning:

15x3=0/:15x3=0/3x=0 15x^3=0 \hspace{8pt}\text{/}:15\\ x^3=0 \hspace{8pt}\text{/}\sqrt[3]{\hspace{6pt}}\\ \boxed{x=0}

In solving the equation above, we first divided both sides of the equation by the term with the unknown and then extracted a cube root for both sides of the equation.

(In this case extracting an odd root for the right side of the equation yielded one possibility)

Or:

x2=0x=2 x-2=0\\ \boxed{x=2}

Let's summarize the solution of the equation:

15x430x3=015x3(x2)=015x3=0x=0x2=0x=2x=0,2 15x^4-30x^3=0 \\ \downarrow\\ 15x^3(x-2)=0 \\ \downarrow\\ 15x^3=0 \rightarrow\boxed{ x=0}\\ x-2=0\rightarrow \boxed{x=2}\\ \downarrow\\ \boxed{x=0,2}

Therefore the correct answer is answer B.

Answer

x=0,2 x=0,2

Exercise #4

x2x=0 x^2-x=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

x2x=0 x^2-x=0

First let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and letters in this case is x x and this is because the first power is the lowest power in the equation and therefore is included both in the term with the second power and in the term with the first power, any power higher than this is not included in the term with the first power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms in the expression, so we'll continue and perform the factoring:

x2x=0x(x1)=0 x^2-x=0 \\ \downarrow\\ x(x-1)=0

Let's continue and address the fact that in the left side of the equation we got in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

meaning:

x=0 \boxed{x=0}

or:

x1=0x=1 x-1=0\\ \downarrow\\ \boxed{x=1}

Let's summarize then the solution to the equation:

x2x=0x(x1)=0x=0x=0x1=0x=1x=0,1 x^2-x=0 \\ \downarrow\\ x(x-1)=0 \\ \downarrow\\ x=0 \rightarrow\boxed{ x=0}\\ x-1=0 \rightarrow \boxed{x=1}\\ \downarrow\\ \boxed{x=0,1}

Therefore the correct answer is answer B.

Answer

x=0,1 x=0,1

Exercise #5

12x43x3=0 12x^4-3x^3=0

Video Solution

Step-by-Step Solution

To solve this polynomial equation, we'll follow these steps:

  • Step 1: Identify and factor out the greatest common factor (GCF).
  • Step 2: Solve the resulting simpler equations for xx.
  • Step 3: Verify the solutions.

Now, let's work through each step:

Step 1: Factor out the Greatest Common Factor (GCF)

The given equation is 12x43x3=0 12x^4 - 3x^3 = 0 .
Both terms share a common factor of 3x3 3x^3 . Factoring out this common factor, we get:

3x3(4x1)=0 3x^3(4x - 1) = 0

Step 2: Solve the factored equation

We now have two factors: 3x3 3x^3 and (4x1) (4x - 1) . Set each factor to zero to find possible solutions:

  • For the factor 3x3=0 3x^3 = 0 :
    Solving this gives x3=0 x^3 = 0 , which implies x=0 x = 0 .
  • For the factor 4x1=0 4x - 1 = 0 :
    Solving this gives 4x=1 4x = 1 , leading to x=14 x = \frac{1}{4} .

Step 3: Verification

Substitute x=0 x = 0 and x=14 x = \frac{1}{4} back into the original equation to verify:

  • Substituting x=0 x = 0 :
    12(0)43(0)3=0 12(0)^4 - 3(0)^3 = 0 , which is true.
  • Substituting x=14 x = \frac{1}{4} :
    Calculations show 12(14)43(14)3=0 12\left(\frac{1}{4}\right)^4 - 3\left(\frac{1}{4}\right)^3 = 0 , which also holds true.
Therefore, the solutions to the problem are x=0 x = 0 and x=14 x = \frac{1}{4} .

The correct choice from the given options is x=0,14 x = 0, \frac{1}{4} .

Therefore, the solution to the problem is x=0,14 x=0,\frac{1}{4} .

Answer

x=0,14 x=0,\frac{1}{4}

Exercise #6

Solve for x:

7x514x4=0 7x^5-14x^4=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

7x514x4=0 7x^5-14x^4=0

First, let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and variables in this case is 7x4 7x^4 since the fourth power is the lowest power in the equation and therefore is included both in the term with the fifth power and the term with the fourth power, any power higher than this is not included in the term with the fourth power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms for the variables,

For the numbers, note that 14 is a multiple of 7, therefore 7 is the largest common factor for the numbers in both terms of the expression,

Let's continue and perform the factoring:

7x514x4=07x4(x2)=0 7x^5-14x^4=0 \\ \downarrow\\ 7x^4(x-2)=0

Let's continue and consider the fact that in the left side of the equation we got in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

Meaning:

7x4=0/:7x4=0/4x=±0x=0 7x^4=0 \hspace{8pt}\text{/}:7\\ x^4=0 \hspace{8pt}\text{/}\sqrt[4]{\hspace{6pt}}\\ x=\pm0\\ \boxed{x=0}

In solving the equation above, we first divided both sides of the equation by the term with the variable, and then we took the fourth root of both sides of the equation.

(In this case, taking an even root of the right side of the equation will yield two possibilities - positive and negative but since we're dealing with zero, we get only one answer)

Or:

x2=0x=2 x-2=0\\ \boxed{x=2}

Let's summarize the solution of the equation:

7x514x4=07x4(x2)=07x4=0x=0x2=0x=2x=0,2 7x^5-14x^4=0 \\ \downarrow\\ 7x^4(x-2)=0 \\ \downarrow\\ 7x^4=0 \rightarrow\boxed{ x=0}\\ x-2=0\rightarrow \boxed{x=2}\\ \downarrow\\ \boxed{x=0,2}

Therefore the correct answer is answer A.

Answer

x=0,2 x=0,2

Exercise #7

7x821x7=0 7x^8-21x^7=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

7x821x7=0 7x^8-21x^7=0

First, let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and variables in this case is 7x7 7x^7 since the seventh power is the lowest power in the equation and therefore is included in both the term with the eighth power and the term with the seventh power. Any power higher than this is not included in the term with the seventh power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor for variables,

For the numbers, we notice that 21 is a multiple of 7, therefore 7 is the largest common factor for numbers in both terms of the expression,

Let's continue and perform the factoring:

7x821x7=07x7(x3)=0 7x^8-21x^7=0 \\ \downarrow\\ 7x^7(x-3)=0

Let's continue and address the fact that in the left side of the equation we obtained in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

Meaning:

7x7=0/:7x7=0/7x=0 7x^7=0 \hspace{8pt}\text{/}:7\\ x^7=0 \hspace{8pt}\text{/}\sqrt[7]{\hspace{6pt}}\\ \boxed{x=0}

In solving the equation above, we first divided both sides of the equation by the term with the variable and then extracted a seventh root from both sides of the equation.

(In this case, extracting an odd root from the right side of the equation yielded one possibility)

Or:

x3=0x=3 x-3=0\\ \boxed{x=3}

Let's summarize the solution of the equation:

7x821x7=07x7(x3)=07x7=0x=0x3=0x=3x=0,3 7x^8-21x^7=0 \\ \downarrow\\ 7x^7(x-3)=0 \\ \downarrow\\ 7x^7=0 \rightarrow\boxed{ x=0}\\ x-3=0\rightarrow \boxed{x=3}\\ \downarrow\\ \boxed{x=0,3}

Therefore, the correct answer is answer B.

Answer

x=0,3 x=0,3

Exercise #8

8xx4=0 8x-x^4=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

8xx4=0 8x-x^4=0

First note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and variables in this case is x x because the first power is the lowest power in the equation and therefore is included both in the term with the fourth power and in the term with the first power. Any power higher than this is not included in the term with the first power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms in the expression, so we'll continue and perform the factoring:

8xx4=0x(8x3)=0 8x-x^4=0 \\ \downarrow\\ x(8-x^3)=0

Let's continue and address the fact that on the left side of the equation we got in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

meaning:

x=0 \boxed{x=0}

or:

8x3=08=x3/3x=2 8-x^3=0\\ 8=x^3\hspace{8pt}\text{/}\sqrt[3]{\hspace{6pt}}\\ \downarrow\\ \boxed{x=2} (in this case taking the odd root of the left side of the equation will yield only one possibility)

Let's summarize the solution of the equation:

8xx4=0x(8x3)=0x=08x3=0x=2x=0,2 8x-x^4=0 \\ \downarrow\\ x(8-x^3)=0 \\ \downarrow\\ \boxed{ x=0}\\ 8-x^3=0 \rightarrow \boxed{x=2}\\ \downarrow\\ \boxed{x=0,2}

Therefore the correct answer is answer A.

Answer

x=0,2 x=0,2

Exercise #9

Solve for x:

28x87x7=0 28x^8-7x^7=0

Video Solution

Step-by-Step Solution

To solve this problem, we need to apply the following steps:

  • Step 1: Identify the highest factor common to all terms and factor it out.
  • Step 2: Set each factor equal to zero and solve for xx.
  • Step 3: Validate solutions within the context of the problem statement.

Now, following these steps:

Step 1: Identify and factor out the greatest common factor:

The given equation is 28x87x7=028x^8 - 7x^7 = 0.

The greatest common factor (GCF) of the terms 28x828x^8 and 7x77x^7 is 7x77x^7.

We can factor the equation as:

7x7(4x1)=0 7x^7(4x - 1) = 0 .

Step 2: Set each factor equal to zero:

For 7x7=07x^7 = 0, dividing both sides by 7 yields x7=0x^7 = 0, which implies x=0x = 0.

For 4x1=04x - 1 = 0, solve for xx:

4x=14x = 1

x=14x = \frac{1}{4}

Step 3: Verify solutions:

The values x=0x = 0 and x=14x = \frac{1}{4} both satisfy the original equation, as substituting them back results in 00.

Thus, the solutions to the equation are x=0x = 0 and x=14x = \frac{1}{4}.

The answer, based on the choices provided, is: Answers a and b are correct.

Answer

Answers a and b are correct.

Exercise #10

Solve for x:

x825x6=0 x^8-25x^6=0

Video Solution

Step-by-Step Solution

To solve the equation x825x6=0 x^8 - 25x^6 = 0 , we start by noticing that both terms share a common factor of x6 x^6 . We can factor out x6 x^6 from the expression:

x6(x225)=0 x^6(x^2 - 25) = 0

According to the zero-product property, a product is zero if and only if at least one of the factors is zero. Therefore, we have two separate equations to solve:

  • x6=0 x^6 = 0
  • x225=0 x^2 - 25 = 0

For x6=0 x^6 = 0 :

x=0 x = 0

For x225=0 x^2 - 25 = 0 , this can be seen as a difference of squares, which factors as:

(x5)(x+5)=0 (x - 5)(x + 5) = 0

Again, using the zero-product property, we solve the factors:

  • x5=0 x - 5 = 0 gives x=5 x = 5
  • x+5=0 x + 5 = 0 gives x=5 x = -5

The solutions to the equation are therefore x=0,x=5, x = 0, x = 5, and x=5 x = -5 .

The correct answer choice is "Answers a + b", where ±5 \pm 5 and 0 0 are included as solutions.

Answer

Answers a + b

Exercise #11

x4+2x2=0 x^4+2x^2=0

Video Solution

Step-by-Step Solution

To solve the equation x4+2x2=0x^4 + 2x^2 = 0, we will use the technique of factoring. Let's proceed step-by-step:

First, notice that both terms x4x^4 and 2x22x^2 have a common factor of x2x^2. We can factor x2x^2 out from the equation:

x2(x2+2)=0x^2(x^2 + 2) = 0

Now, to solve for xx, we apply the Zero Product Property, which gives us that at least one of the factors must be zero:

  • x2=0x^2 = 0 or
  • x2+2=0x^2 + 2 = 0

Solving the first case, x2=0x^2 = 0:

x=0x = 0

For the second case, x2+2=0x^2 + 2 = 0, we reach:

x2=2x^2 = -2

Since x2=2x^2 = -2 has no real solutions (squares of real numbers are non-negative), we can conclude that this equation doesn't provide additional real solutions.

Therefore, the only real solution to the given equation is x=0x = 0.

The correct choice from the provided options is:

x=0 x=0

Answer

x=0 x=0

Exercise #12

x1016x6=0 x^{10}-16x^6=0

Video Solution

Step-by-Step Solution

To solve the equation x1016x6=0 x^{10} - 16x^6 = 0 , follow these steps:

  • Step 1: Notice that the common factor in both terms is x6 x^6 . Factor it out:
  • x6(x416)=0 x^6(x^4 - 16) = 0

  • Step 2: Apply the zero product property, which states if a product equals zero, at least one of the factors must be zero.
    Therefore, we have:
  • x6=0 x^6 = 0 or x416=0 x^4 - 16 = 0

  • Step 3: Solve x6=0 x^6 = 0 :
  • The solution to this is x=0 x = 0 .

  • Step 4: Solve x416=0 x^4 - 16 = 0 :
    • Rewrite it as x4=16 x^4 = 16
    • Take the fourth root of both sides:
    • x=±164=±2 x = \pm\sqrt[4]{16} = \pm2

    Thus, x=2 x = 2 or x=2 x = -2 .

Conclusion: The solutions are x=±2 x = \pm 2 and x=0 x = 0 .

Therefore, the correct answer is: Answers a and c

Answer

Answers a and c

Exercise #13

x14x7=0 x^{14}-x^7=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

x14x7=0 x^{14}-x^7=0

First, let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and letters in this case is x7 x^{7} since the seventh power is the lowest power in the equation and therefore is included both in the term with the 14th power and in the term with the seventh power, any power higher than this is not included in the term with the lowest seventh power, and therefore this is the term with the highest power that can be factored out as a common factor from all terms for the letters,

Let's continue then and perform the factoring:

x14x7=0x7(x71)=0 x^{14}-x^7=0 \\ \downarrow\\ x^{7}(x^7-1)=0

Let's continue and address the fact that in the left side of the equation we got in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

Meaning:

x7=0/7x=0 x^{7}=0 \hspace{8pt}\text{/}\sqrt[7]{\hspace{6pt}}\\ \boxed{x=0}

In solving the above equation, we extracted a 99th root for both sides of the equation.

(In this case, extracting an odd-order root to the right side of the equation yielded one possibility)

Or:

x71=0x7=1/7x=1 x^7-1=0\\ x^7=1\hspace{8pt}\text{/}\sqrt[7]{\hspace{6pt}}\\ \boxed{x=1}

In solving the above equation, we first isolated the variable (because it's possible..) on one side and then extracted a seventh root for both sides of the equation.

(In this case, again, extracting an odd-order root to the right side of the equation yielded one possibility)

Let's summarize then the solution of the equation:

x14x7=0x7(x71)=0x7=0x=0x71=0x=1x=0,1 x^{14}-x^7=0 \\ \downarrow\\ x^{7}(x^7-1)=0 \\ \downarrow\\ x^{7}=0 \rightarrow\boxed{ x=0}\\ x^{7}-1=0\rightarrow \boxed{x=1}\\ \downarrow\\ \boxed{x=0,1}

Therefore the correct answer is answer D.

Answer

Answers a + b

Exercise #14

x7+5x6=0 x^7+5x^6=0

Solve the above equation for X.

Video Solution

Step-by-Step Solution

The equation in the problem is:

x7+5x6=0 x^7+5x^6=0

First, let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and letters in this case is x6 x^6 since the sixth power is the lowest power in the equation and therefore is included in both the term with the seventh power and the term with the sixth power. Any power higher than this is not included in the term with the sixth power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms in the expression. Let's continue and perform the factoring:

x7+5x6=0x6(x+5)=0 x^7+5x^6=0 \\ \downarrow\\ x^6(x+5)=0

Let's continue and address the fact that in the left side of the equation we got in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

meaning:

x6=0/6x=±0x=0 x^6=0 \hspace{8pt}\text{/}\sqrt[6]{\hspace{6pt}}\\ x=\pm0\\ \boxed{x=0} (In this case, taking the even root of the right side of the equation will indeed yield two possibilities, positive and negative, but since we're dealing with zero, we'll get only one possibility)

Or:

x+5=0x=5 x+5=0\\ \boxed{x=-5}

Let's summarize the solution of the equation:

x7+5x6=0x6(x+5)=0x6=0x=0x+5=0x=5x=0,5 x^7+5x^6=0 \\ \downarrow\\ x^6(x+5)=0\\ \downarrow\\ x^6=0 \rightarrow\boxed{ x=0}\\ x+5=0 \rightarrow \boxed{x=-5}\\ \downarrow\\ \boxed{x=0,-5}

Therefore the correct answer is answer D.

Answer

Correct answers: a + b

Exercise #15

2x904x89=0 2x^{90}-4x^{89}=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

2x904x89=0 2x^{90}-4x^{89}=0 Let's pay attention to the left side:

The expression can be broken down into factors by taking out a common factor, The greatest common factor for the numbers and letters in this case is 2x89 2x^{89} since the power of 89 is the lowest power in the equation and therefore included both in the term where the power is 90 and in the term where the power is 89.

Any power higher than that is not included in the term where the power of 89 is the lowest, and therefore it is the term with the highest power that can be taken out of all the terms in the expression as a common factor for the variables.

For the numbers, note that the number 4 is a multiple of the number 2, so the number 2 is the greatest common factor for the numbers for the two terms in the expression.

Continuing and performing the factorization:

2x904x89=02x89(x2)=0 2x^{90}-4x^{89}=0 \\ \downarrow\\ 2x^{89}(x-2)=0 Let's continue and remember that on the left side of the equation that was obtained in the last step there is an algebraic expression and on the right side the number is 0.

Since the only way to get the result 0 from a product is for at least one of the factors in the product on the left side to be equal to zero,

Meaning:

2x89=0/:2x89=0/89x=0 2x^{89}=0 \hspace{8pt}\text{/}:2\\ x^{89}=0 \hspace{8pt}\text{/}\sqrt[89]{\hspace{6pt}}\\ \boxed{x=0}

Or:

x2=0x=2 x-2=0 \\ \boxed{x=2}

In summary:

2x904x89=02x89(x2)=02x89=0x=0x2=0x=2x=0,2 2x^{90}-4x^{89}=0 \\ \downarrow\\ 2x^{89}(x-2)=0 \\ \downarrow\\ 2x^{89}=0 \rightarrow\boxed{ x=0}\\ x-2=0\rightarrow \boxed{x=2}\\ \downarrow\\ \boxed{x=0,2} And therefore the correct answer is answer a.

Answer

x=0,2 x=0,2

Exercise #16

Simply the following expression:

(x+x)2 (x+\sqrt{x})^2

Video Solution

Step-by-Step Solution

To solve the problem, we undertake the following steps:

  • Identify the components a=xa = x and b=xb = \sqrt{x} in the expression (x+x)2(x + \sqrt{x})^2.
  • Apply the square of sum formula: (a+b)2=a2+2ab+b2(a + b)^2 = a^2 + 2ab + b^2.
  • Substitute the values:
    • a2=x2a^2 = x^2
    • 2ab=2×x×x=2xx2ab = 2 \times x \times \sqrt{x} = 2x\sqrt{x}
    • b2=(x)2=xb^2 = (\sqrt{x})^2 = x
  • Simplifying gives: x2+2xx+xx^2 + 2x\sqrt{x} + x
  • Recognize that this can be factored to yield: x(x+2x+1)x(x + 2\sqrt{x} + 1)

Thus, the simplified expression is x[x+2x+1]\boxed{x[x + 2\sqrt{x} + 1]}.

Answer

x[x+2x+1] x\lbrack x+2\sqrt{x}+1\rbrack

Exercise #17

3x2+9x=0 3x^2+9x=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

3x2+9x=0 3x^2+9x=0

First, let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and letters in this case is 3x 3x because the first power is the lowest power in the equation and therefore is included both in the term with the second power and in the term with the first power. Any power higher than this is not included in the term with the first power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms for the letters,

For the numbers, note that 9 is a multiple of 3, therefore it is the largest common factor for the numbers in both terms of the expression,

Let's continue and perform the factoring:

3x2+9x=03x(x+3)=0 3x^2+9x=0 \\ \downarrow\\ 3x(x+3)=0

Let's continue and address the fact that on the left side of the equation we obtained in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

Meaning:

3x=0/:3x=0 3x=0 \hspace{8pt}\text{/}:3\\ \boxed{x=0}

In solving the above equation, we divided both sides of the equation by the term with the variable,

Or:

x+3=0x=3 x+3=0 \\ \boxed{x=-3}

Let's summarize the solution of the equation:

3x2+9x=03x(x+3)=03x=0x=0x+3=0x=3x=0,3 3x^2+9x=0 \\ \downarrow\\ 3x(x+3)=0 \\ \downarrow\\ 3x=0 \rightarrow\boxed{ x=0}\\ x+3=0\rightarrow \boxed{x=-3}\\ \downarrow\\ \boxed{x=0,-3}

Therefore the correct answer is answer C.

Answer

x=0,x=3 x=0,x=-3

Exercise #18

x54x4=0 x^5-4x^4=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

x54x4=0 x^5-4x^4=0

First note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and variables in this case is x4 x^4 since the fourth power is the lowest power in the equation and therefore is included both in the term with the fifth power and in the term with the fourth power, any power higher than this is not included in the term with the fourth power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms in the expression, so we'll continue and perform the factoring:

x54x4=0x4(x4)=0 x^5-4x^4=0 \\ \downarrow\\ x^4(x-4)=0

Let's continue and address the fact that in the left side of the equation we got in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

meaning:

x4=0/4x=±0x=0 x^4=0 \hspace{8pt}\text{/}\sqrt[4]{\hspace{6pt}}\\ x=\pm0\\ \boxed{x=0} (In this case taking the even root of the right side of the equation will yield two possibilities - positive and negative, however since we're dealing with zero, we get only one solution)

Or:

x4=0x=4 x-4=0\\ \downarrow\\ \boxed{x=4}

Let's summarize the solution of the equation:

x54x4=0x4(x4)=0x4=0x=0x4=0x=4x=0,4 x^5-4x^4=0 \\ \downarrow\\ x^4(x-4)=0 \\ \downarrow\\ x^4=0 \rightarrow\boxed{ x=0}\\ x-4=0 \rightarrow \boxed{x=4}\\ \downarrow\\ \boxed{x=0,4}

Therefore the correct answer is answer C.

Answer

x=4,x=0 x=4,x=0

Exercise #19

x6+x5=0 x^6+x^5=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

x6+x5=0 x^6+x^5=0

First, let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and variables in this case is x5 x^5 because the fifth power is the lowest power in the equation and therefore is included both in the term with the sixth power and in the term with the fifth power. Any power higher than this is not included in the term with the fifth power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms in the expression. We will continue and perform the factoring:

x6+x5=0x5(x+1)=0 x^6+x^5=0 \\ \downarrow\\ x^5(x+1)=0

Let's continue and address the fact that on the left side of the equation we got in the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

meaning:

x5=0/5x=0 x^5=0 \hspace{8pt}\text{/}\sqrt[5]{\hspace{6pt}}\\ \boxed{x=0} (in this case taking the odd root of the right side of the equation will yield one possibility)

or:

x+1=0x=1 x+1=0\\ \boxed{x=-1}

Let's summarize the solution of the equation:

x6+x5=0x5(x+1)=0x5=0x=0x+1=0x=1x=0,1 x^6+x^5=0 \\ \downarrow\\ x^5(x+1)=0 \\ \downarrow\\ x^5=0 \rightarrow\boxed{ x=0}\\ x+1=0 \rightarrow \boxed{x=-1}\\ \downarrow\\ \boxed{x=0,-1}

Therefore the correct answer is answer A.

Answer

x=1,x=0 x=-1,x=0

Exercise #20

x7x6=0 x^7-x^6=0

Video Solution

Step-by-Step Solution

The equation in the problem is:

x7x6=0 x^7-x^6=0

First, let's note that in the left side we can factor the expression using a common factor, the largest common factor for the numbers and letters in this case is x6 x^6 since the sixth power is the lowest power in the equation and therefore is included both in the term with the seventh power and in the term with the sixth power. Any power higher than this is not included in the term with the sixth power, which is the lowest, and therefore this is the term with the highest power that can be factored out as a common factor from all terms in the expression, so we'll continue and perform the factoring:

x7x6=0x6(x1)=0 x^7-x^6=0 \\ \downarrow\\ x^6(x-1)=0

Let's continue and address the fact that in the left side of the equation we got from the last step there is a multiplication of algebraic expressions and on the right side the number 0, therefore, since the only way to get 0 from multiplication is to multiply by 0, at least one of the expressions in the multiplication on the left side must equal zero,

meaning:

x6=0/6x=±0x=0 x^6=0 \hspace{8pt}\text{/}\sqrt[6]{\hspace{6pt}}\\ x=\pm0\\ \boxed{x=0}

(in this case taking the even root of the right side of the equation will yield two possibilities - positive and negative but since we're dealing with zero, we get only one answer)

or:

x1=0x=1 x-1=0\\ \downarrow\\ \boxed{x=1}

Let's summarize the solution of the equation:

x7x6=0x6(x1)=0x6=0x=0x1=0x=1x=0,1 x^7-x^6=0 \\ \downarrow\\ x^6(x-1)=0 \\ \downarrow\\ x^6=0 \rightarrow\boxed{ x=0}\\ x-1=0 \rightarrow \boxed{x=1}\\ \downarrow\\ \boxed{x=0,1}

Therefore the correct answer is answer C.

Answer

x=0,1 x=0,1