Examples with solutions for Solving Quadratic Equations using Factoring: Equations with variables on both sides

Exercise #1

Solve for x:

7(2x+5)=77 7(-2x+5)=77

Video Solution

Step-by-Step Solution

To open parentheses we will use the formula:

a(x+b)=ax+ab a(x+b)=ax+ab

(7×2x)+(7×5)=77 (7\times-2x)+(7\times5)=77

We multiply accordingly

14x+35=77 -14x+35=77

We will move the 35 to the right section and change the sign accordingly:

14x=7735 -14x=77-35

We solve the subtraction exercise on the right side and we will obtain:

14x=42 -14x=42

We divide both sections by -14

14x14=4214 \frac{-14x}{-14}=\frac{42}{-14}

x=3 x=-3

Answer

-3

Exercise #2

Solve for x:

9(2x)=(x+4)3 -9(2-x)=(x+4)\cdot3

Video Solution

Step-by-Step Solution

We open the parentheses in both sections by the distributive property and use the formula:

a(x+b)=ax+ab a(x+b)=ax+ab

18+9x=3x+12 -18+9x=3x+12

We move 3X to the left section, and 18 to the right section and maintain the corresponding signs:

9x3x=12+18 9x-3x=12+18

We add the terms:

6x=30 6x=30

We divide both sections by 6:

6x6=306 \frac{6x}{6}=\frac{30}{6}

x=5 x=5

Answer

5

Exercise #3

Solve for x:

8(2x+4)=6(x4)+3 -8(2x+4)=6(x-4)+3

Video Solution

Step-by-Step Solution

To open parentheses we will use the formula:

a(x+b)=ax+ab a\left(x+b\right)=ax+ab

(8×2x)+(8×4)=(6×x)+(6×4)+3 (-8\times2x)+(-8\times4)=(6\times x)+(6\times-4)+3

We multiply accordingly:

16x32=6x24+3 -16x-32=6x-24+3

Calculate the elements on the right section:

16x32=6x21 -16x-32=6x-21

In the left section we enter the elements with the X and in the left section those without the X, remember to change the plus and minus signs as appropriate when transferring:

32+21=6x+16x -32+21=6x+16x

Calculate the elements accordingly

11=22x -11=22x

We divide the two sections by 22

1122=22x22 -\frac{11}{22}=\frac{22x}{22}

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

Answer

12 -\frac{1}{2}

Exercise #4

Solve for x:

7(2x+3)4(x+2)=5(23x) -7(2x+3)-4(x+2)=5(2-3x)

Video Solution

Step-by-Step Solution

To open parentheses we will use the formula:

a(x+b)=ax+ab a\left(x+b\right)=ax+ab

(7×2x)+(7×3)+(4×x)+(4×2)=(5×2)+(5×3x) (-7\times2x)+(-7\times3)+(-4\times x)+(-4\times2)=(5\times2)+(5\times-3x)

We multiply accordingly:

14x214x8=1015x -14x-21-4x-8=10-15x

We calculate the elements in the left section:

18x29=1015x -18x-29=10-15x

In the left section we enter the elements with the X and in the right section those without the X, remember to change the plus and minus signs as appropriate when transferring:

18x+15x=10+29 -18x+15x=10+29

We calculate the elements accordingly:

3x=39 -3x=39

We divide the two sections by -3:

3x3=393 \frac{-3x}{-3}=\frac{39}{-3}

x=13 x=-13

Answer

-13

Exercise #5

3(b1)4(b+3)=28 3(b-1)-4(-b+3)=-28

Video Solution

Answer

167 -1\frac{6}{7}

Exercise #6

2(x4)+6(x+2)=18 2(x-4)+6(x+2)=-18

Video Solution

Answer

234 -2\frac{3}{4}

Exercise #7

(y5)6(3+y)=7 (y-5)-6(3+y)=7

Video Solution

Answer

6 -6

Exercise #8

Solve for x:

5(2x)+2x=3(4x) 5(2-x)+2x=3(4-x)

Video Solution

Answer

There is no solution.

Exercise #9

Solve for x:

7(x+4)2=5(2x) -7(x+4)-2=5(2-x)

Video Solution

Answer

-20

Exercise #10

Solve for x:

2(3x+2)+1=3(x+8) -2(3x+2)+1=3(x+8)

Video Solution

Answer

-3

Exercise #11

Solve for x:

(x4)3=2(x+6) (x-4)\cdot3=2(x+6)

Video Solution

Answer

24 24

Exercise #12

Solve for X:

8(4x)+4(2x+5)=2(72x) -8(4-x)+4(2x+5)=2(7-2x)

Video Solution

Answer

1310 \frac{13}{10}

Exercise #13

Solve for X:

2(43x)+4(2x4)=8(2x) -2(4-3x)+4(2x-4)=8(2-x)

Video Solution

Answer

2011 \frac{20}{11}

Exercise #14

Solve for X:

2(4+5x)+3(22x)=8(4x) -2(4+5x)+3(2-2x)=8(4-x)

Video Solution

Answer

174 -\frac{17}{4}

Exercise #15

(12x+3)(4x+7)=1 (\frac{1}{2}x+3)-(4x+7)=1

Video Solution

Answer

137 -1\frac{3}{7}