Examples with solutions for Solving Equations Using All Methods: Opening parentheses

Exercise #1

Solve for X:

78(x+4)=3x 7-8(x+4)=-3x

Video Solution

Step-by-Step Solution

To solve the equation 78(x+4)=3x 7 - 8(x + 4) = -3x , we'll go through these steps:

  • Step 1: Distribute 8-8 across the terms inside the parentheses:
  • 78x84=3x 7 - 8 \cdot x - 8 \cdot 4 = -3x
    This simplifies to 78x32=3x 7 - 8x - 32 = -3x .

  • Step 2: Simplify both sides by combining like terms:
  • 732=25 7 - 32 = -25 , so the equation becomes:
    8x25=3x -8x - 25 = -3x .

  • Step 3: Isolate the variable x x by moving all terms involving x x to one side:
  • To move 8x-8x to the right side, add 8x 8x to both sides:
    25=3x+8x -25 = -3x + 8x
    This simplifies to:
    25=5x -25 = 5x .

  • Step 4: Solve for x x by dividing both sides by 5:
  • x=255 x = \frac{-25}{5} , which gives us:
    x=5 x = -5 .

    Therefore, the solution to the equation is x=5 x = -5 .

The correct choice matches this solution as option 5 \boldsymbol{-5} .

Answer

5 -5

Exercise #2

Solve for X:

3(x2)=4 3(x-2)=4

Video Solution

Step-by-Step Solution

To solve the equation 3(x2)=4 3(x-2) = 4 , we follow these detailed steps:

  • Step 1: Apply the distributive property to the left side of the equation. This means multiplying 3 by each term within the parentheses.
  • Step 2: Expand 3(x2) 3(x-2) to get 3x6 3x - 6 .
  • Step 3: The equation is now 3x6=4 3x - 6 = 4 .
  • Step 4: To isolate the term containing x x , add 6 to both sides of the equation. This yields 3x6+6=4+6 3x - 6 + 6 = 4 + 6 , simplifying to 3x=10 3x = 10 .
  • Step 5: Divide both sides of the equation by 3 to solve for x x . So, x=103 x = \frac{10}{3} .

Therefore, the solution to the problem is x=103 x = \frac{10}{3} .

Answer

103 \frac{10}{3}

Exercise #3

Solve for X:

6(x+4)4=8(x+5) 6(x+4)-4=8(x+5)

Video Solution

Step-by-Step Solution

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

  • Expand both sides using the distributive property.
  • Combine like terms and simplify.
  • Isolate the variable x x .

Let's work through the steps in detail:

Step 1: Apply the distributive property:
- Left side: 6(x+4) 6(x+4) expands to 6x+24 6x + 24 .
- Right side: 8(x+5) 8(x+5) expands to 8x+40 8x + 40 .
Substituting back, the equation becomes:

6x+244=8x+40 6x + 24 - 4 = 8x + 40

Step 2: Simplify the equation by combining like terms:
- 24 - 4 simplifies to 20 on the left-hand side.
The equation now is:

6x+20=8x+40 6x + 20 = 8x + 40

Step 3: Isolate the variable x x :
- First, eliminate 6x 6x from the left side by subtracting 6x 6x from both sides:

20=2x+40 20 = 2x + 40

- Next, eliminate 40 from the right side by subtracting 40 from both sides:

2040=2x 20 - 40 = 2x
20=2x -20 = 2x

Step 4: Solve for x x by dividing both sides by 2:

x=202 x = \frac{-20}{2}
x=10 x = -10

Therefore, the solution to the problem is x=10 x = -10 .

Answer

10 -10

Exercise #4

Solve for X:

7(x4)=(6x)×3 7(x-4)=(6-x)\times3

Video Solution

Step-by-Step Solution

The goal is to solve the linear equation 7(x4)=(6x)×3 7(x-4) = (6-x) \times 3 . Follow these steps to find the solution:

  • Step 1: Open the parentheses using the distributive property. This gives us: 7(x4)=7x28 7(x - 4) = 7x - 28 (6x)×3=183x (6 - x) \times 3 = 18 - 3x Thus, the equation becomes: 7x28=183x 7x - 28 = 18 - 3x
  • Step 2: Combine like terms by getting all x x -terms on one side and constant terms on the other. 7x+3x=18+28 7x + 3x = 18 + 28 Simplify to get: 10x=46 10x = 46
  • Step 3: Solve for x x by dividing both sides by 10. x=4610=4.6 x = \frac{46}{10} = 4.6

Therefore, the solution to the problem is x=4.6 x = 4.6 .

Answer

4.6 4.6

Exercise #5

Solve for X:

7(x+5)3(x2)=5 7(x+5)-3(x-2)=5

Video Solution

Step-by-Step Solution

To solve the given equation 7(x+5)3(x2)=5 7(x + 5) - 3(x - 2) = 5 , we follow these steps:

  • Step 1: Apply the distributive property.
    Distribute 7 over (x+5) (x + 5) to obtain 7x+35 7x + 35 .
    Distribute -3 over (x2) (x - 2) to obtain 3x+6 -3x + 6 .
    The equation becomes 7x+353x+6=5 7x + 35 - 3x + 6 = 5 .
  • Step 2: Combine like terms.
    Combine the x x terms 7x 7x and 3x -3x to get 4x 4x .
    Combine the constant terms 35 35 and 6 6 to get 41 41 .
    The equation simplifies to 4x+41=5 4x + 41 = 5 .
  • Step 3: Isolate the variable x x .
    Subtract 41 from both sides: 4x+4141=541 4x + 41 - 41 = 5 - 41 .
    This simplifies to 4x=36 4x = -36 .
    Divide both sides by 4 to solve for x x : x=364 x = \frac{-36}{4} .
    The solution is x=9 x = -9 .

Therefore, the solution to the equation is x=9 x = -9 .

Answer

9 -9

Exercise #6

Solve for X:

7(x4)+3=54(x+5) 7(x-4)+3=5-4(x+5)

Video Solution

Step-by-Step Solution

Let's solve the given equation step by step:

We start with the equation:

7(x4)+3=54(x+5) 7(x-4) + 3 = 5 - 4(x+5)

Step 1: Apply the distributive property to eliminate the parentheses.

The left-hand side becomes:

7(x4)=7x28 7(x-4) = 7x - 28 , so the entire expression on the left is 7x28+3 7x - 28 + 3 .

The right-hand side becomes:

4(x+5)=4x20 -4(x+5) = -4x - 20 , so the whole right side is 54x20 5 - 4x - 20 .

Step 2: Simplify both sides.

Simplify the left-hand side:

7x28+3=7x25 7x - 28 + 3 = 7x - 25 .

Simplify the right-hand side:

54x20=4x15 5 - 4x - 20 = -4x - 15 .

Now the equation reads:

7x25=4x15 7x - 25 = -4x - 15 .

Step 3: Rearrange the equation to isolate x x terms on one side and constants on the other.

Add 4x 4x to both sides:

7x+4x25=4x+4x15 7x + 4x - 25 = -4x + 4x - 15 .

This simplifies to:

11x25=15 11x - 25 = -15 .

Step 4: Solve for x x .

Add 25 to both sides:

11x=10 11x = 10 .

Divide both sides by 11 to solve for x x :

x=1011 x = \frac{10}{11} .

Thus, the solution to the equation is x=1011 x = \frac{10}{11} .

Considering the given choices, the correct answer is choice 3: 1011 \frac{10}{11} .

Answer

1011 \frac{10}{11}

Exercise #7

Solve for X:

6+3(x+4)=73(x2) 6+3(x+4)=7-3(x-2)

Video Solution

Step-by-Step Solution

Let's solve the linear equation 6+3(x+4)=73(x2) 6 + 3(x + 4) = 7 - 3(x - 2) step-by-step.

Step 1: Expand the terms using the distributive property.

On the left side: 3(x+4)=3x+12 3(x + 4) = 3x + 12

On the right side: 3(x2)=3x+6 -3(x - 2) = -3x + 6

Substituting back, the equation becomes:

6+3x+12=73x+6 6 + 3x + 12 = 7 - 3x + 6

Step 2: Simplify both sides by combining like terms.

Left side: 6+12+3x=18+3x 6 + 12 + 3x = 18 + 3x

Right side: 7+63x=133x 7 + 6 - 3x = 13 - 3x

The equation now is:

18+3x=133x 18 + 3x = 13 - 3x

Step 3: Bring all terms involving x x to one side.

Add 3x 3x to both sides:

18+3x+3x=13 18 + 3x + 3x = 13

18+6x=13 18 + 6x = 13

Step 4: Isolate the variable x x .

Subtract 18 from both sides:

6x=1318 6x = 13 - 18

6x=5 6x = -5

Divide both sides by 6:

x=56 x = -\frac{5}{6}

Therefore, the solution to the problem is x=56 x = -\frac{5}{6} .

Answer

56 -\frac{5}{6}

Exercise #8

Solve for X:

5(x4)6(7x)=5x 5(x-4)-6(7-x)=5x

Video Solution

Step-by-Step Solution

To solve the equation 5(x4)6(7x)=5x 5(x-4) - 6(7-x) = 5x , we will simplify both sides and solve for x x step-by-step:

Step 1: Distribute Constants inside Parentheses
Apply the distributive property to simplify each group:
- 5(x4) 5(x-4) becomes 5x20 5x - 20 .
- 6(7x)-6(7-x) becomes 42+6x-42 + 6x.

Resulting Equation:
5x2042+6x=5x 5x - 20 - 42 + 6x = 5x .

Step 2: Combine Like Terms
Combine 5x 5x and 6x 6x , and 20-20 and 42-42:
- 5x+6x=11x 5x + 6x = 11x .
- 2042=62-20 - 42 = -62.
The equation is now: 11x62=5x 11x - 62 = 5x .

Step 3: Isolate the Variable x x
Subtract 5x 5x from both sides to get the x x -terms on one side:
11x5x=62 11x - 5x = 62 .
This simplifies to 6x62=0 6x - 62 = 0 .

Step 4: Solve for x x
Add 62 to both sides to isolate the term with x x :
6x=62 6x = 62 .
Now, divide by 6 to solve for x x :
x=626=31310.33 x = \frac{62}{6} = \frac{31}{3} \approx 10.33 .

Therefore, x10.33 x \approx 10.33 .

Answer

10.33 10.33

Exercise #9

Solve for X:

34(x2)=6x+4(3x) 3-4(x-2)=6x+4(3-x)

Video Solution

Step-by-Step Solution

Let's solve the equation 34(x2)=6x+4(3x) 3-4(x-2)=6x+4(3-x) .

First, apply the distributive property on both sides:

  • For the left side: 34(x2) 3 - 4(x - 2) becomes 34x+8 3 - 4x + 8 , which simplifies to 114x 11 - 4x .
  • For the right side: 6x+4(3x) 6x + 4(3 - x) becomes 6x+124x 6x + 12 - 4x , which simplifies to 2x+12 2x + 12 .

Now the equation is:

114x=2x+12 11 - 4x = 2x + 12

Combine like terms to isolate x x . First, move all terms containing x x to one side and constant terms to the other side:

  • Add 4x 4x to both sides: 11=6x+12 11 = 6x + 12 .
  • Subtract 12 from both sides: 1112=6x 11 - 12 = 6x , which simplifies to 1=6x -1 = 6x .

Finally, solve for x x by dividing both sides by 6:

x=16 x = -\frac{1}{6} .

Therefore, the solution to the problem is x=16 x = -\frac{1}{6} , which corresponds to choice 4.

Answer

16 -\frac{1}{6}

Exercise #10

Solve for X:


3(x+2)=5(2x) 3(x+2)=5(2-x)

Video Solution

Step-by-Step Solution

To solve the given equation 3(x+2)=5(2x)3(x+2) = 5(2-x), we will follow these steps:

  • Step 1: Distribute on both sides of the equation.

For the left side, distribute 33 over (x+2)(x+2):

3(x+2)=3x+63(x+2) = 3x + 6

For the right side, distribute 55 over (2x)(2-x):

5(2x)=105x5(2-x) = 10 - 5x

  • Step 2: Rewrite the equation with the expanded terms.

The equation becomes:

3x+6=105x3x + 6 = 10 - 5x

  • Step 3: Combine like terms to isolate xx.

First, add 5x5x to both sides to get all xx terms on the left side:

3x+5x+6=103x + 5x + 6 = 10

This simplifies to:

8x+6=108x + 6 = 10

Next, subtract 6 from both sides to isolate the term with xx:

8x=48x = 4

  • Step 4: Solve for xx.

Divide both sides by 8 to solve for xx:

x=48x = \frac{4}{8}

Simplify the fraction:

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

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

Answer

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

Exercise #11

(a+3a)×(5+2)=112 (a+3a)\times(5+2)=112

Calculate a a

Video Solution

Step-by-Step Solution

We begin by solving the two exercises inside of the parentheses:

4a×7=112 4a\times7=112

We then divide each of the sections by 4:

4a×74=1124 \frac{4a\times7}{4}=\frac{112}{4}

In the fraction on the left side we simplify by 4 and in the fraction on the right side we divide by 4:

a×7=28 a\times7=28

Remember that:

a×7=a7 a\times7=a7

Lastly we divide both sections by 7:

a77=287 \frac{a7}{7}=\frac{28}{7}

a=4 a=4

Answer

4

Exercise #12

(7x+3)×(10+4)=238 (7x+3)\times(10+4)=238

Video Solution

Step-by-Step Solution

We begin by solving the addition exercise in the right parenthesis:

(7x+3)+14=238 (7x+3)+14=238

We then multiply each of the terms inside of the parentheses by 14:

(14×7x)+(14×3)=238 (14\times7x)+(14\times3)=238

Following this we solve each of the exercises inside of the parentheses:

98x+42=238 98x+42=238

We move the sections whilst retaining the appropriate sign:

98x=23842 98x=238-42

98x=196 98x=196

Finally we divide the two parts by 98:

9898x=19698 \frac{98}{98}x=\frac{196}{98}

x=2 x=2

Answer

2