Enter an equation or problem

Camera input is not recognized!

Solution - Absolute value equations

Exact form:

x = \frac{10}{7}, 2

x=\frac{10}{7} , 2

Mixed number form:

x = 1 \frac{3}{7}, 2

x=1\frac{3}{7} , 2

Decimal form:

x = 1.429, 2

x=1.429 , 2

See steps

Step-by-step explanation

1. Rewrite the equation without absolute value bars

Use the rules:
$| x | = | y |$ → $x = \pm y$ and $| x | = | y |$ → $\pm x = y$
to write all four options of the equation
$| - 5 x + 8 | = | 2 x - 2 |$
without the absolute value bars:

$\| x \| = \| y \|$	$\| - 5 x + 8 \| = \| 2 x - 2 \|$
$x = + y$	$(- 5 x + 8) = (2 x - 2)$
$x = - y$	$(- 5 x + 8) = - (2 x - 2)$
$+ x = y$	$(- 5 x + 8) = (2 x - 2)$
$- x = y$	$- (- 5 x + 8) = (2 x - 2)$

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:

$\| x \| = \| y \|$	$\| - 5 x + 8 \| = \| 2 x - 2 \|$
$x = + y$ , $+ x = y$	$(- 5 x + 8) = (2 x - 2)$
$x = - y$ , $- x = y$	$(- 5 x + 8) = - (2 x - 2)$

2. Solve the two equations for x

11 additional steps

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

Subtract from both sides:

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

Group like terms:

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

Simplify the arithmetic:

$- 7 x + 8 = (2 x - 2) - 2 x$

Group like terms:

$- 7 x + 8 = (2 x - 2 x) - 2$

Simplify the arithmetic:

$- 7 x + 8 = - 2$

Subtract from both sides:

$(- 7 x + 8) - 8 = - 2 - 8$

Simplify the arithmetic:

$- 7 x = - 2 - 8$

Simplify the arithmetic:

$- 7 x = - 10$

Divide both sides by :

$\frac{(- 7 x)}{- 7} = \frac{- 10}{- 7}$

Cancel out the negatives:

$\frac{7 x}{7} = \frac{- 10}{- 7}$

Simplify the fraction:

$x = \frac{- 10}{- 7}$

Cancel out the negatives:

$x = \frac{10}{7}$

14 additional steps

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

Expand the parentheses:

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

Add to both sides:

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

Group like terms:

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

Simplify the arithmetic:

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

Group like terms:

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

Simplify the arithmetic:

$- 3 x + 8 = 2$

Subtract from both sides:

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

Simplify the arithmetic:

$- 3 x = 2 - 8$

Simplify the arithmetic:

$- 3 x = - 6$

Divide both sides by :

$\frac{(- 3 x)}{- 3} = \frac{- 6}{- 3}$

Cancel out the negatives:

$\frac{3 x}{3} = \frac{- 6}{- 3}$

Simplify the fraction:

$x = \frac{- 6}{- 3}$

Cancel out the negatives:

$x = \frac{6}{3}$

Find the greatest common factor of the numerator and denominator:

$x = \frac{(2 \cdot 3)}{(1 \cdot 3)}$

Factor out and cancel the greatest common factor:

$x = 2$

3. List the solutions

$x = \frac{10}{7}, 2$
(2 solution(s))

4. Graph

Each line represents the function of one side of the equation:
$y = | - 5 x + 8 |$
$y = | 2 x - 2 |$
The equation is true where the two lines cross.

How did we do?

Please leave us feedback.

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.

Solution - Absolute value equations

Step-by-step explanation

1. Rewrite the equation without absolute value bars

2. Solve the two equations for x

3. List the solutions

4. Graph

Why learn this

Terms and topics

Related links

Solution - Absolute value equations

Step-by-step explanation

1. Rewrite the equation without absolute value bars

2. Solve the two equations for x

3. List the solutions

4. Graph

Why learn this

Terms and topics

Related links

Latest Related Drills Solved