Enter an equation or problem
Camera input is not recognized!

Solution - Absolute value equations

Exact form: y=92
y=\frac{9}{2}
Mixed number form: y=412
y=4\frac{1}{2}
Decimal form: y=4.5
y=4.5

Other Ways to Solve

Absolute value equations

Step-by-step explanation

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

|y+5|+|y4|=0

Add |y4| to both sides of the equation:

|y+5|+|y4||y4|=|y4|

Simplify the arithmetic

|y+5|=|y4|

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
|y+5|=|y4|
without the absolute value bars:

|x|=|y||y+5|=|y4|
x=+y(y+5)=(y4)
x=y(y+5)=(y4)
+x=y(y+5)=(y4)
x=y(y+5)=(y4)

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||y+5|=|y4|
x=+y , +x=y(y+5)=(y4)
x=y , x=y(y+5)=(y4)

3. Solve the two equations for y

6 additional steps

(-y+5)=-(y-4)

Expand the parentheses:

(-y+5)=-y+4

Add to both sides:

(-y+5)+y=(-y+4)+y

Group like terms:

(-y+y)+5=(-y+4)+y

Simplify the arithmetic:

5=(-y+4)+y

Group like terms:

5=(-y+y)+4

Simplify the arithmetic:

5=4

The statement is false:

5=4

The equation is false so it has no solution.

12 additional steps

(-y+5)=-(-(y-4))

NT_MSLUS_MAINSTEP_RESOLVE_DOUBLE_MINUS:

(-y+5)=y-4

Subtract from both sides:

(-y+5)-y=(y-4)-y

Group like terms:

(-y-y)+5=(y-4)-y

Simplify the arithmetic:

-2y+5=(y-4)-y

Group like terms:

-2y+5=(y-y)-4

Simplify the arithmetic:

2y+5=4

Subtract from both sides:

(-2y+5)-5=-4-5

Simplify the arithmetic:

2y=45

Simplify the arithmetic:

2y=9

Divide both sides by :

(-2y)-2=-9-2

Cancel out the negatives:

2y2=-9-2

Simplify the fraction:

y=-9-2

Cancel out the negatives:

y=92

4. Graph

Each line represents the function of one side of the equation:
y=|y+5|
y=|y4|
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.