Enter an equation or problem
Camera input is not recognized!

Solution - Absolute value equations

Exact form: x=1,9
x=1 , -9

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
|2x+3|=|x+6|
without the absolute value bars:

|x|=|y||2x+3|=|x+6|
x=+y(2x+3)=(x+6)
x=y(2x+3)=(x+6)
+x=y(2x+3)=(x+6)
x=y(2x+3)=(x+6)

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||2x+3|=|x+6|
x=+y , +x=y(2x+3)=(x+6)
x=y , x=y(2x+3)=(x+6)

2. Solve the two equations for x

10 additional steps

(2x+3)=(-x+6)

Add to both sides:

(2x+3)+x=(-x+6)+x

Group like terms:

(2x+x)+3=(-x+6)+x

Simplify the arithmetic:

3x+3=(-x+6)+x

Group like terms:

3x+3=(-x+x)+6

Simplify the arithmetic:

3x+3=6

Subtract from both sides:

(3x+3)-3=6-3

Simplify the arithmetic:

3x=63

Simplify the arithmetic:

3x=3

Divide both sides by :

(3x)3=33

Simplify the fraction:

x=33

Simplify the fraction:

x=1

8 additional steps

(2x+3)=-(-x+6)

Expand the parentheses:

(2x+3)=x-6

Subtract from both sides:

(2x+3)-x=(x-6)-x

Group like terms:

(2x-x)+3=(x-6)-x

Simplify the arithmetic:

x+3=(x-6)-x

Group like terms:

x+3=(x-x)-6

Simplify the arithmetic:

x+3=6

Subtract from both sides:

(x+3)-3=-6-3

Simplify the arithmetic:

x=63

Simplify the arithmetic:

x=9

3. List the solutions

x=1,9
(2 solution(s))

4. Graph

Each line represents the function of one side of the equation:
y=|2x+3|
y=|x+6|
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.