Examples with solutions for Solving an Equation by Multiplication/ Division: Equations with variables on both sides

Exercise #1

Solve for X:

3x=18 3x=18

Video Solution

Step-by-Step Solution

We use the formula:

ax=b a\cdot x=b

x=ba x=\frac{b}{a}

Note that the coefficient of X is 3.

Therefore, we will divide both sides by 3:

3x3=183 \frac{3x}{3}=\frac{18}{3}

Then divide accordingly:

x=6 x=6

Answer

6 6

Exercise #2

7y=27 -7y=-27

Video Solution

Step-by-Step Solution

To solve the equation 7y=27-7y = -27, we need to isolate the variable yy. We do this by performing the following steps:

  • Step 1: Divide both sides of the equation by 7-7 to solve for yy.

Performing this operation gives us:

7y÷(7)=27÷(7)-7y \div (-7) = -27 \div (-7)

Simplifying both sides, we have:

y=277y = \frac{27}{7}

To express 277\frac{27}{7} as a mixed number, we divide 27 by 7:

  • 27 divided by 7 equals 3 with a remainder of 6. Hence, 277=367\frac{27}{7} = 3\frac{6}{7}.

Therefore, the solution to the equation is y=367y = 3\frac{6}{7}.

Among the given choices, option 1 matches our result.

Therefore, the solution to the problem is y=367 y = 3\frac{6}{7} .

Answer

367 3\frac{6}{7}

Exercise #3

Solve for X:

8x=5 8x=5

Video Solution

Step-by-Step Solution

To solve the equation 8x=5 8x = 5 , follow these steps:

  • Step 1: Identify the equation 8x=5 8x = 5 , where x x is the unknown variable.
  • Step 2: To isolate x x , divide both sides of the equation by 8.
    This step involves equivalent operations to maintain equality.
  • Step 3: Perform the division on both sides:
    8x8=58\frac{8x}{8} = \frac{5}{8}.
    This simplifies to x=58 x = \frac{5}{8} .

Now, let's outline these steps in detail:

We begin with the equation 8x=5 8x = 5 .

Dividing both sides by the coefficient of x x , which is 8, gives:

8x8=58\frac{8x}{8} = \frac{5}{8}.

This simplifies directly to:

x=58 x = \frac{5}{8} .

Therefore, the solution to the problem is x=58 x = \frac{5}{8} .

Answer

58 \frac{5}{8}

Exercise #4

Solve for X:

5x=3 5x=3

Video Solution

Step-by-Step Solution

To solve the equation 5x=3 5x = 3 , we will isolate x x by using division:

  • Step 1: Recognize that x x is multiplied by 5. To isolate x x , we need to undo this multiplication.
  • Step 2: Divide both sides of the equation by 5. This step uses the Division Property of Equality:

5x5=35\frac{5x}{5} = \frac{3}{5}

Step 3: Simplify both sides. The left side simplifies to x x (because 5x5=x \frac{5x}{5} = x ), and the right side is 35 \frac{3}{5} .

Hence, the solution to the equation 5x=3 5x = 3 is x=35 x = \frac{3}{5} .

Answer

35 \frac{3}{5}

Exercise #5

Solve for X:

7x=4 7x=4

Video Solution

Step-by-Step Solution

To solve the equation 7x=4 7x = 4 , we will follow these steps:

  • Step 1: We start with the equation 7x=4 7x = 4 .

  • Step 2: Our goal is to isolate x x . Since x x is multiplied by 7, we will divide both sides of the equation by 7.

  • Step 3: Performing division: x=47 x = \frac{4}{7}

Therefore, the solution to the equation 7x=4 7x = 4 is x=47 x = \frac{4}{7} .

Answer

47 \frac{4}{7}

Exercise #6

Solve for X:

x4=3 \frac{x}{4}=3

Video Solution

Step-by-Step Solution

We use the formula:

ax=b a\cdot x=b

x=ba x=\frac{b}{a}

We multiply the numerator by X and write the exercise as follows:

x4=3 \frac{x}{4}=3

We multiply by 4 to get rid of the fraction's denominator:

4×x4=3×4 4\times\frac{x}{4}=3\times4

Then, we remove the common factor from the left side and perform the multiplication on right side to obtain:

x=12 x=12

Answer

12 12

Exercise #7

6x=18 -6x=18

Video Solution

Step-by-Step Solution

To solve the equation 6x=18-6x = 18, we need to isolate the variable xx.

Our equation is:

6x=18-6x = 18

The variable xx is multiplied by 6-6. To undo this operation and solve for xx, we divide both sides of the equation by 6-6. This will isolate xx on one side of the equation:

6x6=186\frac{-6x}{-6} = \frac{18}{-6}

Simplifying both sides, we find:

x=3x = -3

Thus, the solution to the equation 6x=18-6x = 18 is x=3x = -3.

Therefore, the correct answer is x=3x = -3.

Answer

3 -3

Exercise #8

Solve for X:

6x=3 6x=3

Video Solution

Step-by-Step Solution

To solve the equation 6x=3 6x = 3 , follow these steps:

Step 1: We aim to isolate x x . Divide both sides of the equation by 6 to remove the coefficient attached to x x :

x=36 x = \frac{3}{6}

Step 2: Simplify the fraction on the right side:

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

Therefore, the solution to the equation 6x=3 6x = 3 is x=12 x = \frac{1}{2} .

Answer

12 \frac{1}{2}

Exercise #9

Solve for X:

4x=18 4x=\frac{1}{8}

Video Solution

Step-by-Step Solution

To solve the equation 4x=18 4x = \frac{1}{8} , we need to isolate x x . We do this by dividing both sides of the equation by the coefficient of x x , which is 4:

  • Step 1: Write the original equation: 4x=18 4x = \frac{1}{8} .
  • Step 2: Divide both sides by 4 to solve for x x :

x=184 x = \frac{\frac{1}{8}}{4}

  • Step 3: Simplify the right-hand side by multiplying fractions, recalling that dividing by a number is equivalent to multiplying by its reciprocal:

x=18×14=1×18×4=132 x = \frac{1}{8} \times \frac{1}{4} = \frac{1 \times 1}{8 \times 4} = \frac{1}{32}

Thus, the solution to the equation is x=132 x = \frac{1}{32} .

Answer

132 \frac{1}{32}

Exercise #10

Solve for X:

5x=38 5x=\frac{3}{8}

Video Solution

Step-by-Step Solution

ax=cb ax=\frac{c}{b}

x=cba x=\frac{c}{b\cdot a}

Answer

340 \frac{3}{40}

Exercise #11

Solve for X:

4x7=x+5 4x - 7 = x + 5

Video Solution

Step-by-Step Solution

To solve forx x , first, get all terms involving x x on one side and constants on the other. Start from:

4x7=x+5 4x - 7 = x + 5

Subtract x x from both sides to simplify:

3x7=5 3x - 7 = 5

Add 7 to both sides to isolate the terms withx x :

3x=12 3x = 12

Divide each side by 3 to solve forx x :

x=4 x = 4

Thus, x x is 4 4 .

Answer

4 4

Exercise #12

5x+7=32 5x+7=32

Video Solution

Step-by-Step Solution

To solve this linear equation, follow these steps:

  • Step 1: Isolate the term with x x by subtracting 7 from both sides of the equation.
  • Step 2: Perform the subtraction to simplify the equation.
  • Step 3: Divide both sides by 5 to solve for x x .

Let’s perform each step:

Step 1: Subtract 7 from both sides:
5x+77=327 5x + 7 - 7 = 32 - 7

This simplifies to:
5x=25 5x = 25

Step 2: Divide both sides by 5 to isolate x x :
x=255 x = \frac{25}{5}

Perform the division:
x=5 x = 5

Hence, the solution to the equation 5x+7=32 5x + 7 = 32 is x=5 x = 5 .

Answer

x=5 x=5

Exercise #13

8x+4=4 8x+4=4

Video Solution

Step-by-Step Solution

We will solve the given linear equation 8x+4=4 8x + 4 = 4 step-by-step:

Step 1: Subtract 4 from both sides of the equation to begin isolating the variable x x :

8x+44=44 8x + 4 - 4 = 4 - 4

This simplifies to:

8x=0 8x = 0

Step 2: Divide both sides of the equation by 8 to solve for x x :

8x8=08 \frac{8x}{8} = \frac{0}{8}

This results in:

x=0 x = 0

Therefore, the solution to the equation is x=0 x = 0 .

Answer

x=0 x=0

Exercise #14

14x6=134 14x-6=134

Video Solution

Step-by-Step Solution

To solve the equation 14x6=134 14x - 6 = 134 , follow these steps:

  • Step 1: Isolate the term involving x x . We do this by adding 6 to both sides of the equation to eliminate the constant term:

14x6+6=134+6 14x - 6 + 6 = 134 + 6

This simplifies to:

14x=140 14x = 140

  • Step 2: Solve for x x by dividing both sides by 14 (the coefficient of x x ):

14x14=14014 \frac{14x}{14} = \frac{140}{14}

This gives us:

x=10 x = 10

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

Answer

x=10 x=10

Exercise #15

8002xx=803 800-2x-x=803

Video Solution

Step-by-Step Solution

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

  • Step 1: Combine like terms on the left side of the equation.
  • Step 2: Isolate the variable x x on one side of the equation.
  • Step 3: Solve for x x and simplify the result.

Now, let's work through each step:
Step 1: The left side of the equation is 8002xx 800 - 2x - x . Combine the terms with x x :
This becomes 8003x=803 800 - 3x = 803 .

Step 2: Subtract 800 from both sides to isolate the term with x x :
8003x800=803800 800 - 3x - 800 = 803 - 800
This simplifies to 3x=3 -3x = 3 .

Step 3: Divide both sides by -3 to solve for x x :
x=33 x = \frac{3}{-3}
Thus, x=1 x = -1 .

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

Answer

x=1 x=-1

Exercise #16

Solve for X:

3x+8=7x12 -3x+8=7x-12

Video Solution

Step-by-Step Solution

We will solve the equation step by step:

Given equation:
3x+8=7x12 -3x + 8 = 7x - 12

  • Step 1: Move all x x -terms to one side by adding 3x 3x to both sides.
    3x+3x+8=7x+3x12 -3x + 3x + 8 = 7x + 3x - 12
    This simplifies to:
    8=10x12 8 = 10x - 12
  • Step 2: Move constant terms to the opposite side by adding 12 12 to both sides.
    8+12=10x12+12 8 + 12 = 10x - 12 + 12
    Which simplifies to:
    20=10x 20 = 10x
  • Step 3: Solve for x x by dividing both sides by 10 10 .
    2010=10x10 \frac{20}{10} = \frac{10x}{10}
    This gives us:
    x=2 x = 2

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

Answer

2 2

Exercise #17

Solve for X:

18x=34 \frac{1}{8}x=\frac{3}{4}

Video Solution

Step-by-Step Solution

We use the formula:

abx=cd \frac{a}{b}x=\frac{c}{d}

x=bcad x=\frac{bc}{ad}

We multiply the numerator by X and write the exercise as follows:

x8=34 \frac{x}{8}=\frac{3}{4}

We multiply both sides by 8 to eliminate the fraction's denominator:

8×x8=34×8 8\times\frac{x}{8}=\frac{3}{4}\times8

On the left side, it seems that the 8 is reduced and the right section is multiplied:

x=244=6 x=\frac{24}{4}=6

Answer

6 6

Exercise #18

Solve for X:

25x=38 \frac{2}{5}x=\frac{3}{8}

Video Solution

Step-by-Step Solution

To solve the equation 25x=38 \frac{2}{5}x = \frac{3}{8} , we need to isolate xx. We can achieve this by multiplying both sides by the reciprocal of 25\frac{2}{5}.

Step 1: Multiply both sides by 52\frac{5}{2}, which is the reciprocal of 25\frac{2}{5}:

52×25x=52×38 \frac{5}{2} \times \frac{2}{5}x = \frac{5}{2} \times \frac{3}{8}

Step 2: Simplify the left side. The 52\frac{5}{2} and 25\frac{2}{5} cancel each other out:

x=5×32×8 x = \frac{5 \times 3}{2 \times 8}

Step 3: Simplify the right side by multiplying the numerators and denominators:

x=1516 x = \frac{15}{16}

Therefore, the solution to the equation is 1516\boxed{\frac{15}{16}}, which matches choice 3.

Answer

1516 \frac{15}{16}

Exercise #19

Solve for X:

78x=25 \frac{7}{8}x=\frac{2}{5}

Video Solution

Step-by-Step Solution

To solve for x x in the equation 78x=25 \frac{7}{8}x = \frac{2}{5} , we will follow these steps:

  • Multiply both sides of the equation by the reciprocal of 78\frac{7}{8}, which is 87\frac{8}{7}.
  • Simplify the resulting expression to find the value of x x .

Let's work through these steps:

First, multiply both sides by 87\frac{8}{7} to isolate x x on the left side.

87×78x=87×25 \frac{8}{7} \times \frac{7}{8}x = \frac{8}{7} \times \frac{2}{5}

This simplifies to:

x=87×25 x = \frac{8}{7} \times \frac{2}{5}

Now, perform the multiplication of the fractions:

x=8×27×5=1635 x = \frac{8 \times 2}{7 \times 5} = \frac{16}{35}

Thus, the value of x x is 1635\frac{16}{35}.

Answer

1635 \frac{16}{35}

Exercise #20

Solve for X:

10x=611 10x=\frac{6}{11}

Video Solution

Step-by-Step Solution

To solve this problem, we need to isolate x x by performing the following steps:

  • Step 1: Start with the given equation 10x=611 10x = \frac{6}{11} .
  • Step 2: Divide both sides of the equation by 10 to solve for x x . x=61110 x = \frac{\frac{6}{11}}{10}
  • Step 3: Simplify the fraction on the right. Dividing a fraction by a whole number involves multiplying the denominator by that number: x=611×10=6110 x = \frac{6}{11 \times 10} = \frac{6}{110}
  • Step 4: Reduce the fraction 6110\frac{6}{110}. The greatest common divisor of 6 and 110 is 2: x=6÷2110÷2=355 x = \frac{6 \div 2}{110 \div 2} = \frac{3}{55}

Thus, the solution to the problem is x=355 x = \frac{3}{55} .

Answer

355 \frac{3}{55}

More Questions

Solving Equations by using Addition/ Subtraction