Enter an equation or problem
Camera input is not recognized!

Solution - Absolute value equations

Exact form: x=2,6
x=2 , -6

Other Ways to Solve

Absolute value equations

Step-by-step explanation

1. Rewrite the equation without absolute value bars

Use the rules:
|x|=|y|x=±y and |x|=|y|±x=y
to write all four options of the equation
|3x2|=|2x+8|
without the absolute value bars:

|x|=|y||3x2|=|2x+8|
x=+y(3x2)=(2x+8)
x=y(3x2)=(2x+8)
+x=y(3x2)=(2x+8)
x=y(3x2)=(2x+8)

When simplified, equations x=+y and +x=y are the same and equations x=y and x=y are the same, so we end up with only 2 equations:

|x|=|y||3x2|=|2x+8|
x=+y , +x=y(3x2)=(2x+8)
x=y , x=y(3x2)=(2x+8)

2. Solve the two equations for x

11 additional steps

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

Add to both sides:

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

Group like terms:

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

Simplify the arithmetic:

5x-2=(-2x+8)+2x

Group like terms:

5x-2=(-2x+2x)+8

Simplify the arithmetic:

5x2=8

Add to both sides:

(5x-2)+2=8+2

Simplify the arithmetic:

5x=8+2

Simplify the arithmetic:

5x=10

Divide both sides by :

(5x)5=105

Simplify the fraction:

x=105

Find the greatest common factor of the numerator and denominator:

x=(2·5)(1·5)

Factor out and cancel the greatest common factor:

x=2

8 additional steps

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

Expand the parentheses:

(3x-2)=2x-8

Subtract from both sides:

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

Group like terms:

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

Simplify the arithmetic:

x-2=(2x-8)-2x

Group like terms:

x-2=(2x-2x)-8

Simplify the arithmetic:

x2=8

Add to both sides:

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

Simplify the arithmetic:

x=8+2

Simplify the arithmetic:

x=6

3. List the solutions

x=2,6
(2 solution(s))

4. Graph

Each line represents the function of one side of the equation:
y=|3x2|
y=|2x+8|
The equation is true where the two lines cross.

Why learn this

We encounter absolute values almost daily. For example: If you walk 3 miles to school, do you also walk minus 3 miles when you go back home? The answer is no because distances use absolute value. The absolute value of the distance between home and school is 3 miles, there or back.
In short, absolute values help us deal with concepts like distance, ranges of possible values, and deviation from a set value.