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

Exercise #1

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+5−5=9−54x + 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 #2

2b−3b+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:

2b−3b=5−4 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 #3

20+20x−3x=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+20x−3x=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.

20x−3x=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=88−20 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 #4

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 #5

2y+12−5y+30=0 2y+12-5y+30=0

y=? y=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 2y+12−5y+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:
    2y−5y+12+30=0 2y - 5y + 12 + 30 = 0
  • Step 2: Calculate the combined terms.
    2y−5y=−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=−42−3 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

800−2x−x=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 800−2x−x 800 - 2x - x . Combine the terms with x x :
This becomes 800−3x=803 800 - 3x = 803 .

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

Step 3: Divide both sides by -3 to solve for x x :
x=3−3 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 #7

m+3m−17m+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+3m−17m+6=−20 m + 3m - 17m + 6 = -20 .
Combine the coefficients of m m :

(1+3−17)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+6−6=−20−6 -13m + 6 - 6 = -20 - 6

Simplifies to:

−13m=−26 -13m = -26

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

m=−26−13 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 #8

4a+5−24+a=−2a 4a+5-24+a=-2a

a=? a=?

Video Solution

Step-by-Step Solution

To solve the equation 4a+5−24+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+5−24=−2a 4a + a + 5 - 24 = -2a

This simplifies to:

5a−19=−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 #9

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:

5x−3x+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 #10

Solve for X:

7x−3=4x+9 7x - 3 = 4x + 9

Video Solution

Step-by-Step Solution

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

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

7x−4x−3=9 7x - 4x - 3 = 9

2. Simplify the equation:

3x−3=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 #11

Solve for X:

4x−7=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:

4x−7=x+5 4x - 7 = x + 5

Subtract x x from both sides to simplify:

3x−7=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

Find the value of the parameter X

x+3−8x=4+3−x 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+3−8x=4+3−x x + 3 - 8x = 4 + 3 - x .
Combine like terms on each side:
Left side: x−8x+3=−7x+3 x - 8x + 3 = -7x + 3
Right side: 4−x+3=7−x 4 - x + 3 = 7 - x
So the equation becomes: −7x+3=7−x -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=7−x+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+3−3=7−3 -6x + 3 - 3 = 7 - 3 −6x=4 -6x = 4
Now, divide both sides by −6-6 to solve for x x : x=4−6=−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 #13

Solve for X:

−5x+20−3x=40+2−6x -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+20−3x -5x + 20 - 3x simplifies to −8x+20 -8x + 20 .

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

The equation now is:
−8x+20=42−6x -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:
20−42=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 #14

Solve for X:

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

Video Solution

Step-by-Step Solution

To solve the equation 22x−12+1612=14.5x−12 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: 22x−12+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:
22x−0.5+16.5=22x+16 22x - 0.5 + 16.5 = 22x + 16.

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

The right-hand side remains as 14.5x−12 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+16−14.5x=−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+16−16=−12−16 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:
x≈−3.73 x \approx -3.73 .

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

Answer

−3.73 -3.73

Exercise #15

Solve for X:

17.5−18x−5.5x=19.2+1412−5x 17.5-18x-5.5x=19.2+14\frac{1}{2}-5x

Video Solution

Step-by-Step Solution

To solve the equation 17.5−18x−5.5x=19.2+1412−5x 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 −18x−5.5x -18x - 5.5x , which simplifies to −23.5x -23.5x .
  • On the right side, simplify 19.2+14.5−5x 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:

17.5−23.5x=33.7−5x 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:
  • 17.5−23.5x+5x=33.7 17.5 - 23.5x + 5x = 33.7
  • This further simplifies to 17.5−18.5x=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=33.7−17.5 -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=16.2−18.5≈−0.8757 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 #16

2−5x+4−1x=0 2-5x+4-1x=0

Video Solution

Step-by-Step Solution

To solve the equation 2−5x+4−1x=0 2 - 5x + 4 - 1x = 0 , we proceed as follows:

  • Step 1: Simplify the left side of the equation.

Combine the constant terms 22 and 44:

2+4=6 2 + 4 = 6

Combine the terms involving x x :

−5x−1x=−6x-5x - 1x = -6x

Thus, the equation becomes:

6−6x=0 6 - 6x = 0

  • Step 2: Isolate the variable x x .

Move 66 to the other side of the equation by subtracting 66 from both sides:

−6x=−6 -6x = -6

Divide both sides by −6-6 to solve for x x :

x=−6−6=1 x = \frac{-6}{-6} = 1

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

Answer

x=1 x=1

Exercise #17

Find the value of the parameter X

−3x+8−11=40x+5x+9 -3x+8-11=40x+5x+9

Video Solution

Step-by-Step Solution

To solve the equation −3x+8−11=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+8−11=−3x−3 -3x + 8 - 11 = -3x - 3 .

The equation is now: −3x−3=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: −3x−3+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: −3−9=48x+9−9 -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 #18

6x⋅2−4+2x+2=5 6x\cdot2-4+2x+2=5

Video Solution

Step-by-Step Solution

To solve the linear equation 6x⋅2−4+2x+2=5 6x \cdot 2 - 4 + 2x + 2 = 5 , follow these steps:

  • Step 1: Simplify the expression on the left-hand side of the equation.
  • Step 2: Combine like terms to reduce the equation.
  • Step 3: Isolate the variable x x to determine its value.

Let's simplify and solve the given equation:

Step 1: Simplify the expression 6x⋅2−4+2x+2 6x \cdot 2 - 4 + 2x + 2 .
This becomes 12x−4+2x+2 12x - 4 + 2x + 2 .

Step 2: Combine like terms.
Combine the terms involving x x : 12x+2x=14x 12x + 2x = 14x .
Combine the constants: −4+2=−2-4 + 2 = -2.
This results in the equation 14x−2=5 14x - 2 = 5 .

Step 3: Isolate x x .
Add 2 to both sides to eliminate the constant on the left:
14x−2+2=5+2 14x - 2 + 2 = 5 + 2 .
This simplifies to 14x=7 14x = 7 .
Next, divide both sides by 14 to solve for x x :
x=714 x = \frac{7}{14} .

Simplify the fraction:x=12 x = \frac{1}{2} .

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

Answer

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

Exercise #19

5x−4⋅3+4x+3x=0 5x-4\cdot3+4x+3x=0

Video Solution

Step-by-Step Solution

To solve this linear equation 5x−4⋅3+4x+3x=0 5x - 4 \cdot 3 + 4x + 3x = 0 , follow these steps:

  • Simplify the expression: First, calculate the product 4⋅3 4 \cdot 3 . This equals 12 12 .

  • Substitute back into the equation: 5x−12+4x+3x=0 5x - 12 + 4x + 3x = 0 .

  • Combine like terms:

    • The terms involving x x are 5x 5x , 4x 4x , and 3x 3x . Add these together: 5x+4x+3x=12x 5x + 4x + 3x = 12x .

  • The equation now simplifies to 12x−12=0 12x - 12 = 0 .

  • Isolate x x : Add 12 12 to both sides of the equation to eliminate the constant term on the left:

    • 12x−12+12=0+12 12x - 12 + 12 = 0 + 12 , which simplifies to 12x=12 12x = 12 .

  • Solve for x x : Divide both sides by 12 12 to solve for x x :

    • x=1212=1 x = \frac{12}{12} = 1 .

The solution to the equation is x=1 x = 1 .

Verify with the given choices, we find that the correct answer is: x=1 x = 1 .

Answer

x=1 x=1

Exercise #20

2x⋅4−1+x+2=19 2x\cdot4-1+x+2=19

Video Solution

Step-by-Step Solution

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

  • Step 1: Eliminate multiplication by distributing 2x⋅4 2x \cdot 4 .
  • Step 2: Combine like terms on the left side of the equation.
  • Step 3: Isolate the variable x x by moving constants to the opposite side.

Let's work through these steps:

Step 1: The given equation is 2x⋅4−1+x+2=19 2x \cdot 4 - 1 + x + 2 = 19 .
Distribute the multiplication on 2x⋅4 2x \cdot 4 to get 8x 8x :

8x−1+x+2=19 8x - 1 + x + 2 = 19

Step 2: Combine the like terms (8x 8x and x x ):

9x−1+2=19 9x - 1 + 2 = 19

Simplify further by combining constants −1+2-1 + 2 to get:

9x+1=19 9x + 1 = 19

Step 3: Isolate x x by subtracting 1 from both sides:

9x=18 9x = 18

Finally, divide both sides by 9 to solve for x x :

x=189=2 x = \frac{18}{9} = 2

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

Answer

x=2 x=2