Solving Equations by Factoring: Solving the problem

Examples with solutions for Solving Equations by Factoring: Solving the problem

Exercise #1

Find the value of the parameter x.

2x27x+5=0 2x^2-7x+5=0

Video Solution

Step-by-Step Solution

We will factor using trinomials, remembering that there is more than one solution for the value of X:

2x27x+5=0 2x^2-7x+5=0

We will factor -7X into two numbers whose product is 10:

2x25x2x+5=0 2x^2-5x-2x+5=0

We will factor out a common factor:

2x(x1)5(x1)=0 2x(x-1)-5(x-1)=0

(2x5)(x1)=0 (2x-5)(x-1)=0

Therefore:

x1=0 x-1=0 x=1 x=1

Or:

2x5=0 2x-5=0

2x=5 2x=5

x=2.5 x=2.5

Answer

x=1,x=2.5 x=1,x=2.5

Exercise #2

Find the value of the parameter x.

x225=0 x^2-25=0

Video Solution

Step-by-Step Solution

We will factor using the shortened multiplication formulas:

a2b2=(ab)(a+b) a^2-b^2=(a-b)(a+b) (ab)2=a22ab+b2 (a-b)^2=a^2-2ab+b^2

(a+b)2=a2+2ab+b2 (a+b)^2=a^2+2ab+b^2

Let's remember that there might be more than one solution for the value of x.

According to the first formula:

x2=a2 x^2=a^2

We'll take the square root:

x=a x=a

25=b2 25=b^2

We'll take the square root:

b=5 b=5

We'll use the first shortened multiplication formula:

a2b2=(ab)(a+b) a^2-b^2=(a-b)(a+b)

x225=(x5)(x+5)=0 x^2-25=(x-5)(x+5)=0

Therefore:

x+5=0 x+5=0

x=5 x=-5

Or:

x5=0 x-5=0

x=5 x=5

Answer

x=5,x=5 x=5,x=-5

Exercise #3

Find the value of the parameter x.

(x5)2=0 (x-5)^2=0

Video Solution

Step-by-Step Solution

We will factor using the shortened multiplication formulas:

a2b2=(ab)(a+b) a^2-b^2=(a-b)(a+b) (ab)2=a22ab+b2 (a-b)^2=a^2-2ab+b^2

(a+b)2=a2+2ab+b2 (a+b)^2=a^2+2ab+b^2

Let's remember that there might be more than one solution for the value of x.

According to one solution, we'll take the square root:

(x5)2=0 (x-5)^2=0

x5=0 x-5=0

x=5 x=5

According to the second solution, we'll use the shortened multiplication formula:

(x5)2=x210x+25=0 (x-5)^2=x^2-10x+25=0

We'll use the trinomial:

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

x5=0 x-5=0

x=5 x=5

or

x5=0 x-5=0

x=5 x=5

Therefore, according to all calculations, x=5 x=5

Answer

x=5 x=5

Exercise #4

Solve for x.

x27x12=0 -x^2-7x-12=0

Video Solution

Step-by-Step Solution

First, factor using trinomials and remember that there might be more than one solution for the value of x x :

x27x12=0 -x^2-7x-12=0

Divide by -1:

x2+7x+12=0 x^2+7x+12=0

(x+3)(x+4)=0 (x+3)(x+4)=0

Therefore:

x+4=0 x+4=0

x=4 x=-4

Or:

x+3=0 x+3=0

x=3 x=-3

Answer

x=3,x=4 x=-3,x=-4

Exercise #5

Find the value of the parameter x.

(x4)2+x(x12)=16 (x-4)^2+x(x-12)=16

Video Solution

Step-by-Step Solution

Let's open the parentheses, remembering that there might be more than one solution for the value of X:

(x4)2+x(x12)=16 (x-4)^2+x(x-12)=16

x28x+16+x212x=16 x^2-8x+16+x^2-12x=16

2x220x=0 2x^2-20x=0

2x(x10)=0 2x(x-10)=0

Therefore:

x10=0 x-10=0

x=10 x=10

Or:

2x=0 2x=0

x=0 x=0

Answer

x=0,x=10 x=0,x=10

Exercise #6

Find the value of the parameter x.

12x39x23x=0 12x^3-9x^2-3x=0

Video Solution

Answer

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

Exercise #7

Find the value of the parameter x.

2x(3x)+(x3)2=9 -2x(3-x)+(x-3)^2=9

Video Solution

Answer

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

Exercise #8

Find the value of the parameter x.

(x+5)2=0 (x+5)^2=0

Video Solution

Answer

x=5 x=-5