Enter an equation or problem
Camera input is not recognized!

Solution - Absolute value equations

Exact form: x=-2,12
x=-2 , \frac{1}{2}
Decimal form: x=2,0.5
x=-2 , 0.5

Other Ways to Solve

Absolute value equations

Step-by-step explanation

1. Rewrite the equation with one absolute value terms on each side

|x3||3x+1|=0

Add |3x+1| to both sides of the equation:

|x3||3x+1|+|3x+1|=|3x+1|

Simplify the arithmetic

|x3|=|3x+1|

2. 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
|x3|=|3x+1|
without the absolute value bars:

|x|=|y||x3|=|3x+1|
x=+y(x3)=(3x+1)
x=y(x3)=((3x+1))
+x=y(x3)=(3x+1)
x=y(x3)=(3x+1)

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||x3|=|3x+1|
x=+y , +x=y(x3)=(3x+1)
x=y , x=y(x3)=((3x+1))

3. Solve the two equations for x

13 additional steps

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

Subtract from both sides:

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

Group like terms:

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

Simplify the arithmetic:

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

Group like terms:

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

Simplify the arithmetic:

2x3=1

Add to both sides:

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

Simplify the arithmetic:

2x=1+3

Simplify the arithmetic:

2x=4

Divide both sides by :

(-2x)-2=4-2

Cancel out the negatives:

2x2=4-2

Simplify the fraction:

x=4-2

Move the negative sign from the denominator to the numerator:

x=-42

Find the greatest common factor of the numerator and denominator:

x=(-2·2)(1·2)

Factor out and cancel the greatest common factor:

x=2

12 additional steps

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

Expand the parentheses:

(x-3)=-3x-1

Add to both sides:

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

Group like terms:

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

Simplify the arithmetic:

4x-3=(-3x-1)+3x

Group like terms:

4x-3=(-3x+3x)-1

Simplify the arithmetic:

4x3=1

Add to both sides:

(4x-3)+3=-1+3

Simplify the arithmetic:

4x=1+3

Simplify the arithmetic:

4x=2

Divide both sides by :

(4x)4=24

Simplify the fraction:

x=24

Find the greatest common factor of the numerator and denominator:

x=(1·2)(2·2)

Factor out and cancel the greatest common factor:

x=12

4. List the solutions

x=-2,12
(2 solution(s))

5. Graph

Each line represents the function of one side of the equation:
y=|x3|
y=|3x+1|
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.