Enter an equation or problem
Camera input is not recognized!

Solution - Absolute value equations

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

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

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

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

2. Solve the two equations for x

8 additional steps

x=2·(x+3)

Expand the parentheses:

x=2x+2·3

Simplify the arithmetic:

x=2x+6

Subtract from both sides:

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

Simplify the arithmetic:

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

Group like terms:

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

Simplify the arithmetic:

x=6

Multiply both sides by :

-x·-1=6·-1

Remove the one(s):

x=6·-1

Simplify the arithmetic:

x=6

12 additional steps

x=2·(-(x+3))

Expand the parentheses:

x=2·(-x-3)

x=2·-x+2·-3

Group like terms:

x=(2·-1)x+2·-3

Multiply the coefficients:

x=-2x+2·-3

Simplify the arithmetic:

x=2x6

Add to both sides:

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

Simplify the arithmetic:

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

Group like terms:

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

Simplify the arithmetic:

3x=6

Divide both sides by :

(3x)3=-63

Simplify the fraction:

x=-63

Find the greatest common factor of the numerator and denominator:

x=(-2·3)(1·3)

Factor out and cancel the greatest common factor:

x=2

3. List the solutions

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

4. Graph

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