Examples with solutions for Solving an Equation by Multiplication/ Division: Combining like terms

Exercise #1

2b3b+4=5 2b-3b+4=5

b=? b=\text{?}

Video Solution

Step-by-Step Solution

Let's first arrange the equation so that on the left-hand side we have the terms with the coefficient b b and on the right-hand side the numbers without the coefficient b b .

Remember that when we move terms across the equals sign, the plus and minus signs will change accordingly:

2b3b=54 2b-3b=5-4

Let's now solve the subtraction exercise on both sides:

1b=1 -1b=1

Finally, we can divide both sides by -1 to find our answer:

b=1 b=-1

Answer

-1

Exercise #2

m+3m17m+6=20 m+3m-17m+6=-20

m=? m=\text{?}

Video Solution

Step-by-Step Solution

To solve the problem, we will use the following steps:

  • Step 1: Simplify the equation by combining like terms.
  • Step 2: Isolate the variable m m using algebraic methods.
  • Step 3: Solve for m m and verify the solution.

Let's begin:

Step 1: Simplify the equation m+3m17m+6=20 m + 3m - 17m + 6 = -20 .
Combine the coefficients of m m :

(1+317)m+6=20 (1 + 3 - 17)m + 6 = -20

This simplifies to:

13m+6=20 -13m + 6 = -20

Step 2: Isolate m m .
Subtract 6 from both sides:

13m+66=206 -13m + 6 - 6 = -20 - 6

Simplifies to:

13m=26 -13m = -26

Step 3: Solve for m m by dividing both sides by -13:

m=2613 m = \frac{-26}{-13}

The division simplifies to:

m=2 m = 2

Therefore, the solution to the problem is m=2 m = 2 , which corresponds to choice 2 in the given options.

Answer

2

Exercise #3

Solve for X:

7x3=4x+9 7x - 3 = 4x + 9

Video Solution

Step-by-Step Solution

To solve the equation 7x3=4x+9 7x - 3 = 4x + 9 , follow these steps:

1. Subtract 4x 4x from both sides to get:

7x4x3=9 7x - 4x - 3 = 9

2. Simplify the equation:

3x3=9 3x - 3 = 9

3. Add 3 3 to both sides:

3x=12 3x = 12

4. Divide both sides by 3 3 :

x=4 x=4

Answer

4

Exercise #4

Solve for X:

5x+10=3x+18 5x + 10 = 3x + 18

Video Solution

Step-by-Step Solution

To solve the equation 5x+10=3x+18 5x + 10 = 3x + 18 , follow these steps:

1. Subtract 3x 3x from both sides to get:

5x3x+10=18 5x - 3x + 10 = 18

2. Simplify the equation:

2x+10=18 2x + 10 = 18

3. Subtract 10 10 from both sides:

2x=8 2x = 8

4. Divide both sides by 2 2 :

x=4 x = 4

Answer

4

Exercise #5

2y+125y+30=0 2y+12-5y+30=0

y=? y=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 2y+125y+30=0 2y + 12 - 5y + 30 = 0 , follow these steps:

  • Step 1: Simplify the equation by combining like terms.
    Combine the y y terms and the constant terms:
    2y5y+12+30=0 2y - 5y + 12 + 30 = 0
  • Step 2: Calculate the combined terms.
    2y5y=3y 2y - 5y = -3y
    12+30=42 12 + 30 = 42
    Thus, the equation becomes:
    3y+42=0 -3y + 42 = 0
  • Step 3: Isolate the variable y y .
    Subtract 42 from both sides to get:
    3y=42 -3y = -42
  • Step 4: Solve for y y by dividing both sides by 3-3:
    y=423 y = \frac{-42}{-3}
  • Step 5: Simplify the fraction:
    y=14 y = 14

Therefore, the solution to the equation is y=14 y = 14 .

Answer

14 14

Exercise #6

4a+524+a=2a 4a+5-24+a=-2a

a=? a=?

Video Solution

Step-by-Step Solution

To solve the equation 4a+524+a=2a 4a + 5 - 24 + a = -2a , follow these steps:

  • Step 1: Start by combining like terms on the left side of the equation:

4a+a+524=2a 4a + a + 5 - 24 = -2a

This simplifies to:

5a19=2a 5a - 19 = -2a

  • Step 2: Move all terms involving a a to one side of the equation and constant terms to the other side:

Add 2a 2a to both sides to collect all terms with a a :

5a+2a=19 5a + 2a = 19

This simplifies to:

7a=19 7a = 19

  • Step 3: Solve for a a by dividing both sides by 7:

a=197 a = \frac{19}{7}

Thus, the value of a a is 197 \frac{19}{7} , which can be written as a mixed number:

a=257 a = 2\frac{5}{7} .

Upon verifying with the given choices, the correct answer is choice 1: 257 2\frac{5}{7} .

Answer

257 2\frac{5}{7}

Exercise #7

2+3a+4=0 2+3a+4=0

a=? a=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 2+3a+4=0 2 + 3a + 4 = 0 , follow these steps:

  • Step 1: Combine the constant terms on the left side.
    The terms 2 2 and 4 4 can be combined to get 6 6 .
    Hence, the equation becomes 3a+6=0 3a + 6 = 0 .
  • Step 2: Isolate the term with the variable a a .
    Subtract 6 6 from both sides to get 3a=6 3a = -6 .
  • Step 3: Solve for a a by dividing both sides by the coefficient of a a , which is 3 3 .
    Thus, a=63=2 a = \frac{-6}{3} = -2 .

Therefore, the solution to the problem is a=2 a = -2 .

Answer

2 -2

Exercise #8

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 #9

20+20x3x=88 20+20x-3x=88

x=? x=\text{?}

Video Solution

Step-by-Step Solution

To solve this problem, we need to find x x in the equation:

20+20x3x=88 20 + 20x - 3x = 88

Step 1: Combine like terms on the left-hand side of the equation. The terms involving x x are 20x 20x and 3x-3x.

20x3x=17x 20x - 3x = 17x

Thus, the equation becomes:

20+17x=88 20 + 17x = 88

Step 2: Isolate the x x -related terms by moving the constant term to the right-hand side. To do this, subtract 20 from both sides:

17x=8820 17x = 88 - 20

17x=68 17x = 68

Step 3: Solve for x x by dividing both sides of the equation by 17:

x=6817 x = \frac{68}{17}

x=4 x = 4

Therefore, the solution to the problem is x=4 x = 4 .

Answer

4 4

Exercise #10

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 #11

3x+4+x+1=9 3x+4+x+1=9

Video Solution

Step-by-Step Solution

To solve the given equation 3x+4+x+1=93x + 4 + x + 1 = 9, we'll proceed step-by-step:

  • Step 1: Combine like terms on the left side
    Combine the terms with xx: 3x+x=4x3x + x = 4x.
    Combine the constant terms: 4+1=54 + 1 = 5.
    The equation becomes 4x+5=94x + 5 = 9.
  • Step 2: Isolate the variable xx
    Subtract 5 from both sides to move the constant term to the right side:
    4x+55=954x + 5 - 5 = 9 - 5, which simplifies to 4x=44x = 4.
  • Step 3: Solve for xx
    Divide both sides by 4 to solve for xx:
    4x4=44\frac{4x}{4} = \frac{4}{4}, which simplifies to x=1x = 1.

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

Answer

x=1 x=1

Exercise #12

2x+4+283x=x 2x+4+28-3x=x

x=? x=?

Video Solution

Step-by-Step Solution

To solve this problem, we will simplify and solve the linear equation step-by-step:

1. Start with the given equation:
2x+4+283x=x 2x + 4 + 28 - 3x = x

2. Combine like terms on the left side:
(2x3x)+4+28=x (2x - 3x) + 4 + 28 = x

3. This simplifies to:
x+32=x -x + 32 = x

4. Move all terms involving x x to one side of the equation by adding x x to both sides:
32=2x 32 = 2x

5. Finally, divide both sides by 2 to solve for x x :
x=322 x = \frac{32}{2}

6. Simplify to get the solution:
x=16 x = 16

Therefore, the solution to the problem is x=16 \mathbf{x = 16} .

Answer

16

Exercise #13

Find the value of the parameter X

x+38x=4+3x x+3-8x=4+3-x

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow the procedure of simplifying and solving for x x :

  • Step 1: Simplify both sides of the equation.
  • Step 2: Combine like terms and move them to opposite sides to isolate x x .
  • Step 3: Solve for x x by performing necessary arithmetic operations.

Now, let's work through each step:

Step 1: Simplify both sides of the equation.
The given equation is x+38x=4+3x x + 3 - 8x = 4 + 3 - x .
Combine like terms on each side:
Left side: x8x+3=7x+3 x - 8x + 3 = -7x + 3
Right side: 4x+3=7x 4 - x + 3 = 7 - x
So the equation becomes: 7x+3=7x -7x + 3 = 7 - x .

Step 2: Get all terms involving x x on one side of the equation.
Add x x to both sides to combine the x x terms:
7x+x+3=7x+x -7x + x + 3 = 7 - x + x
Simplifies to: 6x+3=7 -6x + 3 = 7

Step 3: Solve for x x .
Subtract 3 from both sides to isolate terms involving x x : 6x+33=73 -6x + 3 - 3 = 7 - 3 6x=4 -6x = 4
Now, divide both sides by 6-6 to solve for x x : x=46=23 x = \frac{4}{-6} = -\frac{2}{3}

Therefore, the solution to the problem is x=23 x = -\frac{2}{3} .

Answer

23 -\frac{2}{3}

Exercise #14

3x+4+8x15=0 3x+4+8x-15=0

x=? x=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 3x+4+8x15=0 3x + 4 + 8x - 15 = 0 , we begin by combining the terms that involve x x and the constant terms:

Step 1: Combine like terms.
The terms involving x x are 3x 3x and 8x 8x . Adding these yields:

11x 11x

The constant terms are +4 +4 and 15-15. Combining these gives:

+415=11 +4 - 15 = -11

Thus, the equation becomes:

11x11=0 11x - 11 = 0

Step 2: Solve for x x .
To isolate x x , add 11 to both sides of the equation:

11x11+11=0+11 11x - 11 + 11 = 0 + 11 11x=11 11x = 11

Now, divide both sides by 11:

x=1111 x = \frac{11}{11} x=1 x = 1

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

Answer

1 1

Exercise #15

Solve for X:

5x+203x=40+26x -5x+20-3x=40+2-6x

Video Solution

Step-by-Step Solution

To solve for x x , let's follow these steps:

  • Step 1: Combine like terms on both sides of the equation.
  • Step 2: Isolate the x x terms on one side.
  • Step 3: Solve for x x .

Let's begin with the left side of the equation:
5x+203x -5x + 20 - 3x simplifies to 8x+20 -8x + 20 .

Next, the right side of the equation:
40+26x 40 + 2 - 6x simplifies to 426x 42 - 6x .

The equation now is:
8x+20=426x -8x + 20 = 42 - 6x .

Step 2: Move all terms containing x x to one side and constant terms to the other:

First, add 8x 8x to both sides to move the x x terms together:
8x+8x+20=42+2x -8x + 8x + 20 = 42 + 2x
which simplifies to 20=42+2x 20 = 42 + 2x .

Next, subtract 42 42 from both sides to get:
2042=2x 20 - 42 = 2x
which simplifies to 22=2x -22 = 2x .

Step 3: Solve for x x by dividing both sides by 2:
x=222=11 x = \frac{-22}{2} = -11 .

Therefore, the solution to the problem is x=11 x = -11 .

Answer

11 -11

Exercise #16

Solve for X:

22x12+1612=14.5x12 22x-\frac{1}{2}+16\frac{1}{2}=14.5x-12

Video Solution

Step-by-Step Solution

To solve the equation 22x12+1612=14.5x12 22x - \frac{1}{2} + 16\frac{1}{2} = 14.5x - 12 , we will follow these steps:
1. Combine like terms on both sides of the equation.
2. Isolate the variable x x .
3. Solve for x x .

Let's start by simplifying each side:

  • Simplify the left-hand side: 22x12+1612 22x - \frac{1}{2} + 16\frac{1}{2} .

The term 1612 16\frac{1}{2} is equivalent to 16.5 16.5 , so the left-hand side becomes:
22x0.5+16.5=22x+16 22x - 0.5 + 16.5 = 22x + 16.

  • Now simplify the right-hand side: 14.5x12 14.5x - 12 .

The right-hand side remains as 14.5x12 14.5x - 12 .

Now, let's collect like terms. Move the term involving x x from the right-hand side to the left:

  • Subtract 14.5x 14.5x from both sides:
    22x+1614.5x=12 22x + 16 - 14.5x = -12

This simplifies to:
7.5x+16=12 7.5x + 16 = -12 .

Next, isolate the constant term. Subtract 16 from both sides:

  • 7.5x+1616=1216 7.5x + 16 - 16 = -12 - 16

This simplifies to:
7.5x=28 7.5x = -28 .

Finally, solve for x x by dividing both sides by 7.5:

  • x=287.5 x = \frac{-28}{7.5}

Calculating the fraction gives approximately:
x3.73 x \approx -3.73 .

Therefore, the solution to the problem is x=3.73 x = -3.73 .

Answer

3.73 -3.73

Exercise #17

14y+12y+512=0 \frac{1}{4}y+\frac{1}{2}y+5-12=0

y=? y=\text{?}

Video Solution

Step-by-Step Solution

To solve the given linear equation, we will follow these steps:

  • Step 1: Combine the terms involving y y .
  • Step 2: Simplify the constants on the right side of the equation.
  • Step 3: Isolate y y to find its value.

Let’s solve the equation 14y+12y+512=0 \frac{1}{4}y + \frac{1}{2}y + 5 - 12 = 0 .

Step 1: Combine the like terms that involve y y .
The coefficients of y y are 14 \frac{1}{4} and 12 \frac{1}{2} . To combine them, we need a common denominator, which is 4. Therefore:

14y+12y=14y+24y=34y \frac{1}{4}y + \frac{1}{2}y = \frac{1}{4}y + \frac{2}{4}y = \frac{3}{4}y .

Step 2: Simplify the constants.
The equation now becomes 34y+512=0 \frac{3}{4}y + 5 - 12 = 0 .
Combine the constants: 512=7 5 - 12 = -7 .

The equation simplifies to 34y7=0 \frac{3}{4}y - 7 = 0 .

Step 3: Isolate y y .
Add 7 to both sides of the equation:
34y=7 \frac{3}{4}y = 7 .

To solve for y y , multiply both sides by the reciprocal of 34 \frac{3}{4} , which is 43 \frac{4}{3} :

y=7×43=283 y = 7 \times \frac{4}{3} = \frac{28}{3} .

Convert the fraction to a mixed number: 283=93+1=9 remainder 1 \frac{28}{3} = 9 \cdot 3 + 1 = 9 \text{ remainder } 1. Thus, 283=913 \frac{28}{3} = 9\frac{1}{3} .

Therefore, the value of y y is 913 9\frac{1}{3} .

Answer

913 9\frac{1}{3}

Exercise #18

Find the value of the parameter X

3x+811=40x+5x+9 -3x+8-11=40x+5x+9

Video Solution

Step-by-Step Solution

To solve the equation 3x+811=40x+5x+9 -3x + 8 - 11 = 40x + 5x + 9 , we need to combine and simplify terms:

  • Simplify each side separately. Start with the right side: 40x+5x+9=45x+9 40x + 5x + 9 = 45x + 9 .
  • Now simplify the left side: 3x+811=3x3 -3x + 8 - 11 = -3x - 3 .

The equation is now: 3x3=45x+9 -3x - 3 = 45x + 9 . Next, move all x x -terms to one side and constants to the other side:

  • Add 3x 3x to both sides: 3x3+3x=45x+9+3x -3x - 3 + 3x = 45x + 9 + 3x , which simplifies to: 3=48x+9 -3 = 48x + 9 .

Then, move the constant term 9 9 to the left side:

  • Subtract 9 9 from both sides: 39=48x+99 -3 - 9 = 48x + 9 - 9 , which simplifies to: 12=48x -12 = 48x .
  • Solve for x x by dividing both sides by 48: x=1248 x = \frac{-12}{48} .
  • Simplify the fraction: x=14 x = -\frac{1}{4} .

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

Answer

14 -\frac{1}{4}

Exercise #19

Solve for X:

17.518x5.5x=19.2+14125x 17.5-18x-5.5x=19.2+14\frac{1}{2}-5x

Video Solution

Step-by-Step Solution

To solve the equation 17.518x5.5x=19.2+14125x 17.5 - 18x - 5.5x = 19.2 + 14\frac{1}{2} - 5x , follow these steps:

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

  • On the left side, combine 18x5.5x -18x - 5.5x , which simplifies to 23.5x -23.5x .
  • On the right side, simplify 19.2+14.55x 19.2 + 14.5 - 5x . The fraction 1412 14\frac{1}{2} is converted to decimal form as 14.5 14.5 , giving 19.2+14.5=33.7 19.2 + 14.5 = 33.7 .

Step 2: Rewrite the equation with the simplified terms:

17.523.5x=33.75x 17.5 - 23.5x = 33.7 - 5x .

Step 3: Get all terms involving x x on one side of the equation and constant terms on the other.

  • Add 5x 5x to both sides to move all x x related terms to the left:
  • 17.523.5x+5x=33.7 17.5 - 23.5x + 5x = 33.7
  • This further simplifies to 17.518.5x=33.7 17.5 - 18.5x = 33.7 .

    Step 4: Isolate the term with x x by subtracting 17.5 17.5 from both sides:

    18.5x=33.717.5 -18.5x = 33.7 - 17.5 .

    The right side evaluates to 16.2 16.2 .

    Thus, we have 18.5x=16.2 -18.5x = 16.2 .

    Step 5: Solve for x x by dividing both sides by 18.5-18.5:

    x=16.218.50.8757 x = \frac{16.2}{-18.5} \approx -0.8757 .

    Rounding 0.8757 -0.8757 to two decimal places gives x=0.87 x = -0.87 .

    Therefore, the solution to the equation is x=0.87 x = -0.87 .

    This corresponds to option 2 in the given choices.

Answer

0.87 -0.87

Exercise #20

2y1yy+4=8y 2y\cdot\frac{1}{y}-y+4=8y

y=? y=\text{?}

Video Solution

Step-by-Step Solution

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

  • Simplify the term 2y1y 2y \cdot \frac{1}{y}
  • Rearrange the equation to group similar terms
  • Solve for y y

Now, let's work through each step:

Step 1: Simplify the expression 2y1y 2y \cdot \frac{1}{y} .

The term 2y1y 2y \cdot \frac{1}{y} simplifies directly to 2 2 since y y in the numerator and denominator cancel each other out assuming y0 y \neq 0 . Therefore, the equation becomes:

2y+4=8y 2 - y + 4 = 8y

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

2+4=6 2 + 4 = 6 , so the equation now is 6y=8y 6 - y = 8y .

Step 3: Rearrange the equation to isolate y y on one side. Add y y to both sides to get rid of the negative y y :

6=8y+y 6 = 8y + y

This simplifies to:

6=9y 6 = 9y

Step 4: Solve for y y by dividing both sides by 9:

y=69 y = \frac{6}{9}

Simplify the fraction to get:

y=23 y = \frac{2}{3}

Therefore, the solution to the problem is 23 \frac{2}{3} .

Answer

23 \frac{2}{3}