Examples with solutions for Solving Equations by using Addition/ Subtraction: Solving an equation using all techniques

Exercise #1

37b+6b+56=90+9 37b+6b+56=90+9

b=? b=\text{?}

Video Solution

Step-by-Step Solution

We begin by simplifying the given equation:

37b+6b+56=90+9 37b + 6b + 56 = 90 + 9

First, we combine like terms on the left side of the equation:

(37+6)b+56 (37 + 6)b + 56

This simplifies to:

43b+56 43b + 56

Now the equation is:

43b+56=99 43b + 56 = 99

Next, we need to isolate b b by moving the constant term to the right side. We do this by subtracting 56 from both sides:

43b=9956 43b = 99 - 56

Simplifying the right-hand side gives us:

43b=43 43b = 43

Finally, to solve for b b , we divide both sides by 43:

b=4343 b = \frac{43}{43}

This simplifies to:

b=1 b = 1

Therefore, the solution to the problem is b=1 b = 1 .

Answer

1

Exercise #2

7y+10y+5=2(y+3) 7y+10y+5=2(y+3)

y=? y=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 7y+10y+5=2(y+3) 7y + 10y + 5 = 2(y + 3) , let's proceed as follows:

  • Step 1: Simplify the left side by combining like terms. The expression 7y+10y 7y + 10y combines to 17y 17y , so we have 17y+5=2(y+3) 17y + 5 = 2(y + 3) .

  • Step 2: Expand the right side. Distribute the 2 across the parenthesis: 2(y+3) 2(y + 3) becomes 2y+6 2y + 6 . The equation now reads 17y+5=2y+6 17y + 5 = 2y + 6 .

  • Step 3: Isolate terms involving y y on one side. Subtract 2y 2y from both sides: 17y2y+5=6 17y - 2y + 5 = 6 , which simplifies to 15y+5=6 15y + 5 = 6 .

  • Step 4: Isolate 15y 15y by subtracting 5 from both sides: 15y=65 15y = 6 - 5 , which simplifies to 15y=1 15y = 1 .

  • Step 5: Solve for y y by dividing both sides by 15: y=115 y = \frac{1}{15} .

Therefore, the solution to the problem is y=115 \mathbf{y = \frac{1}{15}} .

Answer

115 \frac{1}{15}

Exercise #3

6c+7+4c=3(c1) 6c+7+4c=3(c-1)

c=? c=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 6c+7+4c=3(c1) 6c + 7 + 4c = 3(c - 1) , follow these steps:

  • Step 1: Combine like terms on the left side of the equation.
    The like terms are 6c6c and 4c4c. Combining these gives 10c+7=3(c1)10c + 7 = 3(c - 1).
  • Step 2: Apply the distributive property on the right side of the equation.
    The term 3(c1)3(c - 1) expands to 3c33c - 3. Therefore, the equation becomes 10c+7=3c310c + 7 = 3c - 3.
  • Step 3: Move all terms involving cc to one side and constants to the other.
    Subtract 3c3c from both sides: 10c3c+7=310c - 3c + 7 = -3 which simplifies to 7c+7=37c + 7 = -3.
  • Step 4: Isolate the term with cc by subtracting 7 from both sides of the equation.
    This gives 7c=377c = -3 - 7 or 7c=107c = -10.
  • Step 5: Solve for cc.
    Divide both sides by 7: c=107=107c = \frac{-10}{7} = -\frac{10}{7}. This can be converted to a mixed number, giving 137-1\frac{3}{7}.

Therefore, the solution to the equation is c=137 c = -1\frac{3}{7} . This corresponds to choice 2 in the provided answer choices.

Answer

137 -1\frac{3}{7}

Exercise #4

4y7+6y=310y 4y-7+6y=3-10y

y=? y=?

Video Solution

Step-by-Step Solution

To solve the equation 4y7+6y=310y 4y - 7 + 6y = 3 - 10y , follow these steps:

  • Step 1: Combine like terms on both sides of the equation.

The left side simplifies by combining the y y -terms:
4y+6y7=10y7 4y + 6y - 7 = 10y - 7 .

On the right side, there is one y y -term, but we can leave it for the next steps.

  • Step 2: Isolate the y y -terms.

Add 10y 10y to both sides to move all y y -terms to the left side:

10y7+10y=3 10y - 7 + 10y = 3

Simplifying the left side, we get:

20y7=3 20y - 7 = 3

  • Step 3: Isolate y y .

Add 7 7 to both sides to eliminate the constant term on the left:

20y=3+7 20y = 3 + 7

20y=10 20y = 10

Divide both sides by 20 20 to solve for y y :

y=1020 y = \frac{10}{20}

y=12 y = \frac{1}{2}

Therefore, the solution to the problem is y=12 y = \frac{1}{2} .

Answer

12 \frac{1}{2}

Exercise #5

14a+5=20+a \frac{1}{4}a+5=20+a

a=? a=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 14a+5=20+a \frac{1}{4}a + 5 = 20 + a , follow these steps:

  • Step 1: Eliminate the a a variable term on the right side:
    Subtract a a from both sides:
    14a+5a=20+aa \frac{1}{4}a + 5 - a = 20 + a - a
    This simplifies to:
    14aa+5=20 \frac{1}{4}a - a + 5 = 20 .
  • Step 2: Combine like terms involving a a :
    The equation becomes: 14a44a+5=20 \frac{1}{4}a - \frac{4}{4}a + 5 = 20
    Combine them to get:
    34a+5=20 -\frac{3}{4}a + 5 = 20 .
  • Step 3: Isolate the a a term:
    Subtract 5 from both sides:
    34a+55=205 -\frac{3}{4}a + 5 - 5 = 20 - 5
    This simplifies to:
    34a=15 -\frac{3}{4}a = 15 .
  • Step 4: Solve for a a :
    To isolate a a , divide both sides by 34-\frac{3}{4}:
    a=1534=15×43=20 a = \frac{15}{-\frac{3}{4}} = 15 \times -\frac{4}{3} = -20 .
    Therefore, a=20 a = -20 .

Therefore, the solution to the equation is a=20 a = -20 .

Answer

20 -20

Exercise #6

Solve for X:

8+2(x+1)=7x 8+2(x+1)=7x

Video Solution

Step-by-Step Solution

To solve the given equation 8+2(x+1)=7x 8 + 2(x + 1) = 7x , we'll follow these steps:

  • Step 1: Distribute the 2 2 inside the parentheses.
  • Step 2: Combine like terms and simplify both sides.
  • Step 3: Isolate the variable x x on one side of the equation.

Now, let's apply these steps:
Step 1: Distribute the 2 2 in the equation: 2(x+1)=2x+2 2(x + 1) = 2x + 2 Therefore, the equation becomes: 8+2x+2=7x 8 + 2x + 2 = 7x Step 2: Combine like terms on the left side: 10+2x=7x 10 + 2x = 7x Step 3: Isolate x x by moving all terms involving x x to one side and constants to the other: 10=7x2x 10 = 7x - 2x 10=5x 10 = 5x To solve for x x , divide both sides by 5 5 : x=105=2 x = \frac{10}{5} = 2

Therefore, the solution to the equation is x=2 x = 2 .

Answer

2 2

Exercise #7

Solve for X:

3(x4)+8x=14 3-(x-4)+8x=14

Video Solution

Step-by-Step Solution

To solve the equation 3(x4)+8x=14 3 - (x - 4) + 8x = 14 , we will simplify and solve for x x step-by-step:

  • Step 1: Distribute the negative sign inside the parentheses:
    (x4)=x+4- (x - 4) = -x + 4.

  • Step 2: Rewrite the equation with the distributed terms:
    3+(x+4)+8x=143 + (-x + 4) + 8x = 14.

  • Step 3: Simplify by combining like terms:
    Combine the constants: 3+4=73 + 4 = 7
    Combine the xx terms: x+8x=7x-x + 8x = 7x.
    This gives us 7+7x=147 + 7x = 14.

  • Step 4: Isolate the xx term:
    Subtract 7 from both sides: 7x=1477x = 14 - 7.
    This simplifies to 7x=77x = 7.

  • Step 5: Solve for xx by dividing both sides by 7:
    x=77x = \frac{7}{7}.
    Simplifying gives x=1x = 1.

Therefore, the solution to the equation is x=1 x = 1 .

Answer

1 1

Exercise #8

12y+3y10+7(y4)=2y 12y+3y-10+7(y-4)=2y

y=? y=?

Video Solution

Step-by-Step Solution

To solve the equation 12y+3y10+7(y4)=2y12y + 3y - 10 + 7(y - 4) = 2y, follow these detailed steps:

  • Step 1: Apply the distributive property to 7(y4)7(y - 4).

This results in:
12y+3y10+7y28=2y12y + 3y - 10 + 7y - 28 = 2y.

  • Step 2: Combine like terms on the left side of the equation.

Combining terms, we have:
(12y+3y+7y)1028=2y(12y + 3y + 7y) - 10 - 28 = 2y
22y38=2y22y - 38 = 2y.

  • Step 3: Move all terms involving yy to one side of the equation and constant terms to the other side.

Subtract 2y2y from both sides:
22y2y=3822y - 2y = 38
20y=3820y = 38.

  • Step 4: Solve for yy by dividing both sides by 20.

y=3820=1.9y = \frac{38}{20} = 1.9.

Therefore, the solution to the equation is y=1.9 y = 1.9 .

Answer

1.9 1.9

Exercise #9

16a20a+15=2(52a) 16a-20a+15=2(5-2a)

a=? a=\text{?}

Video Solution

Step-by-Step Solution

Let's solve the problem step-by-step:

Step 1: Begin with the original equation:
16a20a+15=2(52a) 16a - 20a + 15 = 2(5 - 2a) .

Step 2: Simplify the left-hand side by combining like terms:
16a20a+15=4a+15 16a - 20a + 15 = -4a + 15 .

Step 3: Apply the distributive property to the right-hand side:
2(52a)=2522a=104a 2(5 - 2a) = 2 \cdot 5 - 2 \cdot 2a = 10 - 4a .

Step 4: Now the equation reads:
4a+15=104a -4a + 15 = 10 - 4a .

Step 5: Attempt to isolate the variable a a by subtracting 10 10 from both sides:
4a+1510=4a -4a + 15 - 10 = -4a .
This simplifies to:
4a+5=4a -4a + 5 = -4a .

Step 6: Subtract 4a -4a from both sides to further simplify the equation:
5=0 5 = 0 .
This is a contradiction, indicating that no solution exists for the equation since a statement like this is never true.

Therefore, the solution to the problem is No solution.

Answer

No solution

Exercise #10

3x+23=4(x+112) 3x+\frac{2}{3}=4(x+\frac{1}{12})

x=? x=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 3x+23=4(x+112)3x + \frac{2}{3} = 4 \left(x + \frac{1}{12}\right), we follow these steps:

Step 1: Distribute the 4 on the right-hand side.

4(x+112)=4x+4124(x + \frac{1}{12}) = 4x + \frac{4}{12} which simplifies to 4x+134x + \frac{1}{3}.

Step 2: Write down the modified equation.

The equation now reads: 3x+23=4x+133x + \frac{2}{3} = 4x + \frac{1}{3}.

Step 3: Rearrange the equation to collect like terms.

Subtract 3x3x from both sides: 3x+233x=4x+133x3x + \frac{2}{3} - 3x = 4x + \frac{1}{3} - 3x.

This simplifies to: 23=x+13\frac{2}{3} = x + \frac{1}{3}.

Step 4: Isolate xx.

Subtract 13\frac{1}{3} from both sides: 2313=x\frac{2}{3} - \frac{1}{3} = x.

This simplifies to: x=13x = \frac{1}{3}.

Therefore, the solution to the equation is 13\boxed{\frac{1}{3}}.

Answer

13 \frac{1}{3}

Exercise #11

13(x+9)=4+23x \frac{1}{3}(x+9)=4+\frac{2}{3}x

x=? x=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 13(x+9)=4+23x \frac{1}{3}(x+9) = 4+\frac{2}{3}x , we will follow these steps:

  • Step 1: Clear fractions by multiplying through by the least common denominator.
  • Step 2: Simplify the equation to combine like terms.
  • Step 3: Solve for x x .

Let's begin:

Step 1: Multiply every term in the equation by 3 to eliminate fractions:

313(x+9)=3(4+23x) 3 \cdot \frac{1}{3}(x+9) = 3 \cdot \left( 4 + \frac{2}{3}x \right)

This simplifies to:

x+9=12+2x x + 9 = 12 + 2x

Step 2: Rearrange the equation to get all x x terms on one side and constant terms on the other:

Subtract 2x 2x from both sides:

x+92x=12 x + 9 - 2x = 12

Which simplifies to:

x+9=12 -x + 9 = 12

Next, subtract 9 from both sides to isolate terms involving x x :

x=3 -x = 3

Step 3: Solve for x x by multiplying both sides by -1:

x=3 x = -3

Thus, the solution to the equation is x=3 x = -3 .

Answer

3-

Exercise #12

a4+7a5=2a+a4+3a(a) a^4+7a-5=2a+a^4+3a-(-a)

a=? a=?

Video Solution

Step-by-Step Solution

First, let's isolate a from the parentheses in the equation on the right side. We'll remember that minus times minus becomes plus, so we get the equation:

a4+7a5=2a+a4+3a+a a^4+7a-5=2a+a^4+3a+a

Let's continue solving the equation on the right side by adding 2a+3a+a=5a+a=6a 2a+3a+a=5a+a=6a

Now the equation we got is:

a4+7a5=6a+a4 a^4+7a-5=6a+a^4

Let's divide both sides by a4 a^4 and we get:

7a5=6a 7a-5=6a

Now let's move 6a to the left side and the number 5 to the right side, remembering to change the plus and minus signs accordingly.

The equation we got now is:

7a6a=5 7a-6a=5

Let's solve the subtraction and we get:

1a=5 1a=5

Let's divide both sides by 1 and we find that a=5 a=5

Answer

5 5

Exercise #13

Solve for X:

6(5+2x)=3x6 6\cdot(5+2x)=3x-6

Video Solution

Step-by-Step Solution

To solve the equation 6(5+2x)=3x66\cdot(5+2x)=3x-6, we will proceed as follows:

  • Step 1: Distribute the 6 within the parentheses on the left side:
    6(5+2x)=30+12x6\cdot(5+2x) = 30 + 12x.
  • Step 2: Substitute the distributed expression into the equation:
    30+12x=3x630 + 12x = 3x - 6.
  • Step 3: Isolate the variable terms on one side:
    Subtract 3x3x from both sides: 30+12x3x=630 + 12x - 3x = -6, which simplifies to 30+9x=630 + 9x = -6.
  • Step 4: Isolate the term containing xx:
    Subtract 30 from both sides: 9x=6309x = -6 - 30, which simplifies to 9x=369x = -36.
  • Step 5: Solve for xx by dividing both sides by 9:
    x=369=4x = \frac{-36}{9} = -4.

Therefore, the solution to the equation is x=4 x = -4 , which corresponds to choice 1.

Answer

4 -4

Exercise #14

Solve the following exercise:

3(4a+8)=27a -3(4a+8)=27a

a=? a=\text{?}

Video Solution

Step-by-Step Solution

To open the parentheses on the left side, we'll use the formula:

a(b+c)=abac -a\left(b+c\right)=-ab-ac

12a24=27a -12a-24=27a

We'll arrange the equation so that the terms with 'a' are on the right side, and maintain the plus and minus signs during the transfer:

24=27a+12a -24=27a+12a

Let's group the terms on the right side:

24=39a -24=39a

Let's divide both sides by 39:

2439=39a39 -\frac{24}{39}=\frac{39a}{39}

2439=a -\frac{24}{39}=a

Note that we can reduce the fraction since both numerator and denominator are divisible by 3:

813=a -\frac{8}{13}=a

Answer

813 -\frac{8}{13}

Exercise #15

Solve for X:

(32x)5=4+12x (3-2x)\cdot5=4+12x

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Distribute and simplify the equation.
  • Step 2: Combine like terms to isolate x x on one side of the equation.
  • Step 3: Solve for x x .

Let's begin solving the equation:

Step 1: Distribute and simplify.
The given equation is (32x)5=4+12x (3 - 2x) \cdot 5 = 4 + 12x .
First, we distribute 5 to both terms inside the parenthesis:

5352x=4+12x 5 \cdot 3 - 5 \cdot 2x = 4 + 12x .

This simplifies to:

1510x=4+12x 15 - 10x = 4 + 12x .

Step 2: Combine like terms to isolate x x on one side of the equation.
Add 10x 10x to both sides to get all terms involving x x on the right-hand side:

15=4+12x+10x 15 = 4 + 12x + 10x .

This simplifies to:

15=4+22x 15 = 4 + 22x .

Subtract 4 from both sides to isolate the term involving x x :

154=22x 15 - 4 = 22x .

This simplifies to:

11=22x 11 = 22x .

Step 3: Solve for x x .
To find x x , divide both sides of the equation by 22:

x=1122 x = \frac{11}{22} .

Upon simplification, 1122 \frac{11}{22} reduces to 12 \frac{1}{2} .

Therefore, the solution to the equation is x=12 x = \frac{1}{2} .

Answer

12 \frac{1}{2}

Exercise #16

74(x)+2x5(x+3)=x -\frac{7}{4}(-x)+2x-5(x+3)=-x

x=? x=\text{?}

Video Solution

Step-by-Step Solution

To solve the given linear equation 74(x)+2x5(x+3)=x -\frac{7}{4}(-x) + 2x - 5(x + 3) = -x , follow these steps:

  • Step 1: Distribute the coefficients across the terms within parentheses:
    The term 74(x) -\frac{7}{4}(-x) becomes 74x \frac{7}{4}x because 74×x=74x -\frac{7}{4} \times -x = \frac{7}{4}x .
    The term 5(x+3) -5(x + 3) can be expanded to 5x15 -5x - 15 .
  • Step 2: Simplify the equation by combining like terms:
    The equation becomes 74x+2x5x15=x \frac{7}{4}x + 2x - 5x - 15 = -x .
  • Step 3: Combine the x x -terms on the left side:
    Combine: 74x+2x5x \frac{7}{4}x + 2x - 5x .
    Converting all terms to a common denominator, 2x=84x 2x = \frac{8}{4}x and 5x=204x -5x = \frac{-20}{4}x . Thus,
    74x+84x204x=54x \frac{7}{4}x + \frac{8}{4}x - \frac{20}{4}x = \frac{-5}{4}x .
  • Step 4: The equation simplifies to:
    54x15=x \frac{-5}{4}x - 15 = -x .
  • Step 5: Isolate the x x terms onto one side:
    Add x x to both sides, treating x -x as 44x \frac{-4}{4}x :
    54x+x15=0 \frac{-5}{4}x + x - 15 = 0 , which simplifies to 14x15=0 \frac{-1}{4}x - 15 = 0 .
  • Step 6: Isolate x x :
    Add 15 15 to both sides:
    14x=15 \frac{-1}{4}x = 15 .
  • Step 7: Solve for x x :
    Multiply both sides by 4 -4 to isolate x x :
    x=15×4 x = 15 \times -4 .
    Thus, x=60 x = -60 .

Therefore, the solution to the equation is x=60 x = -60 .

Answer

60 -60

Exercise #17

(x+2)(2x4)=2x2+x+10 (x+2)(2x-4)=2x^2+x+10

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Expand the left-hand side of the equation.
  • Step 2: Set the equation to standard quadratic form.
  • Step 3: Factor the quadratic equation.
  • Step 4: Solve for x x .

Let's proceed through each step:

Step 1: Expand the left-hand side using the distributive property:

(x+2)(2x4)=x(2x)+x(4)+2(2x)+2(4)(x+2)(2x-4) = x(2x) + x(-4) + 2(2x) + 2(-4)

=2x24x+4x8= 2x^2 - 4x + 4x - 8

=2x28= 2x^2 - 8

Step 2: Set the equation to quadratic form:

Set the expanded result equal to the right-hand side:

2x28=2x2+x+102x^2 - 8 = 2x^2 + x + 10

Step 3: Subtract the right-hand side from the left:

2x28(2x2+x+10)=02x^2 - 8 - (2x^2 + x + 10) = 0

Simplify:

2x282x2x10=02x^2 - 8 - 2x^2 - x - 10 = 0

x18=0-x - 18 = 0

Step 4: Solve for x x :

x=18-x = 18

Divide by -1:

x=18x = -18

Therefore, the solution to the problem is x=18 x = -18 .

Checking against the given choices, choice 1 matches: 18 -18 .

Answer

18 -18

Exercise #18

4(b2+b)13=6b 4(\frac{b}{2}+b)-\frac{1}{3}=6b

b=? b=\text{?}

Video Solution

Step-by-Step Solution

First, we'll expand the parentheses by multiplying each term by 4:

4×b2+4×b13=6b 4\times\frac{b}{2}+4\times b-\frac{1}{3}=6b

Let's then solve the multiplication exercise 4×b2=4b2=2b 4\times\frac{b}{2}=\frac{4b}{2}=2b .

Now the equation is:

2b+4b13=6b 2b+4b-\frac{1}{3}=6b

We can now combine the left-hand side between the two b b terms to get:

6b13=6b 6b-\frac{1}{3}=6b

We'll reduce both sides by 6b 6b , leaving us with:

13=0 -\frac{1}{3}=0

Since the result obtained is impossible, the exercise has no solution.

Answer

No solution

Exercise #19

2x+4513x=5(x+7) 2x+45-\frac{1}{3}x=5(x+7)

x=? x=\text{?}

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Distribute on the right-hand side
  • Step 2: Combine like terms on the left-hand side
  • Step 3: Isolate the variable x x
  • Step 4: Solve for x x

Now, let's work through each step:

Step 1: Distribute on the right-hand side of the equation:

2x+4513x=5(x+7)2x+4513x=5x+35 2x + 45 - \frac{1}{3}x = 5(x + 7) \quad \Rightarrow \quad 2x + 45 - \frac{1}{3}x = 5x + 35

Step 2: Combine like terms on the left-hand side:

Combine 2x 2x and 13x -\frac{1}{3}x on the left:

2x13x=63x13x=53x 2x - \frac{1}{3}x = \frac{6}{3}x - \frac{1}{3}x = \frac{5}{3}x

The equation becomes:

53x+45=5x+35 \frac{5}{3}x + 45 = 5x + 35

Step 3: Move all terms with x x to one side and constants to the other:

53x5x=3545 \frac{5}{3}x - 5x = 35 - 45

Step 4: Simplify and solve for x x :

53x153x=10 \frac{5}{3}x - \frac{15}{3}x = -10 103x=10 -\frac{10}{3}x = -10

Step 5: Solve for x x by dividing both sides by 103-\frac{10}{3}:

x=10103=3 x = \frac{-10}{-\frac{10}{3}} = 3

Therefore, the solution to the problem is x=3 x = 3 .

Answer

3

Exercise #20

Solve for X:

14(x16)+34x=8x11 \frac{1}{4}(x-16)+\frac{3}{4}x=8x-11

Video Solution

Step-by-Step Solution

To solve this problem, we'll eliminate fractions by multiplying the entire equation by the least common denominator, and then proceed with algebraic manipulation:

  • Step 1: Multiply every term by the least common denominator, 4 4 , to eliminate fractions:
    4×(14(x16)+34x)=4×(8x11) 4 \times \left(\frac{1}{4}(x - 16) + \frac{3}{4}x\right) = 4 \times (8x - 11) .

  • Step 2: This simplifies to: 1(x16)+3x=32x44 1(x - 16) + 3x = 32x - 44 .

  • Step 3: Distribute within the brackets:
    x16+3x=32x44 x - 16 + 3x = 32x - 44 .

  • Step 4: Combine like terms on the left-hand side:
    4x16=32x44 4x - 16 = 32x - 44 .

  • Step 5: To isolate terms containing x x , subtract 4x 4x from both sides:
    16=28x44 -16 = 28x - 44 .

  • Step 6: Add 44 to both sides to further isolate x x :
    28=28x 28 = 28x .

  • Step 7: Divide both sides by 28 to solve for x x :
    x=1 x = 1 .

Therefore, the solution to the problem is x=1 x = 1 .

Answer

1 1