Enter an equation or problem

Camera input is not recognized!

Solution - Absolute value equations

Exact form:

x = - 2, \frac{12}{5}

x=-2 , \frac{12}{5}

Mixed number form:

x = - 2, 2 \frac{2}{5}

x=-2 , 2\frac{2}{5}

Decimal form:

x = - 2, 2.4

x=-2 , 2.4

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
$| - 3 x + 5 | = | - 2 x + 7 |$
without the absolute value bars:

$\| x \| = \| y \|$	$\| - 3 x + 5 \| = \| - 2 x + 7 \|$
$x = + y$	$(- 3 x + 5) = (- 2 x + 7)$
$x = - y$	$(- 3 x + 5) = - (- 2 x + 7)$
$+ x = y$	$(- 3 x + 5) = (- 2 x + 7)$
$- x = y$	$- (- 3 x + 5) = (- 2 x + 7)$

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:

$\| x \| = \| y \|$	$\| - 3 x + 5 \| = \| - 2 x + 7 \|$
$x = + y$ , $+ x = y$	$(- 3 x + 5) = (- 2 x + 7)$
$x = - y$ , $- x = y$	$(- 3 x + 5) = - (- 2 x + 7)$

2. Solve the two equations for x

10 additional steps

$(- 3 x + 5) = (- 2 x + 7)$

Add to both sides:

$(- 3 x + 5) + 2 x = (- 2 x + 7) + 2 x$

Group like terms:

$(- 3 x + 2 x) + 5 = (- 2 x + 7) + 2 x$

Simplify the arithmetic:

$- x + 5 = (- 2 x + 7) + 2 x$

Group like terms:

$- x + 5 = (- 2 x + 2 x) + 7$

Simplify the arithmetic:

$- x + 5 = 7$

Subtract from both sides:

$(- x + 5) - 5 = 7 - 5$

Simplify the arithmetic:

$- x = 7 - 5$

Simplify the arithmetic:

$- x = 2$

Multiply both sides by :

$- x \cdot - 1 = 2 \cdot - 1$

Remove the one(s):

$x = 2 \cdot - 1$

Simplify the arithmetic:

$x = - 2$

12 additional steps

$(- 3 x + 5) = - (- 2 x + 7)$

Expand the parentheses:

$(- 3 x + 5) = 2 x - 7$

Subtract from both sides:

$(- 3 x + 5) - 2 x = (2 x - 7) - 2 x$

Group like terms:

$(- 3 x - 2 x) + 5 = (2 x - 7) - 2 x$

Simplify the arithmetic:

$- 5 x + 5 = (2 x - 7) - 2 x$

Group like terms:

$- 5 x + 5 = (2 x - 2 x) - 7$

Simplify the arithmetic:

$- 5 x + 5 = - 7$

Subtract from both sides:

$(- 5 x + 5) - 5 = - 7 - 5$

Simplify the arithmetic:

$- 5 x = - 7 - 5$

Simplify the arithmetic:

$- 5 x = - 12$

Divide both sides by :

$\frac{(- 5 x)}{- 5} = \frac{- 12}{- 5}$

Cancel out the negatives:

$\frac{5 x}{5} = \frac{- 12}{- 5}$

Simplify the fraction:

$x = \frac{- 12}{- 5}$

Cancel out the negatives:

$x = \frac{12}{5}$

3. List the solutions

$x = - 2, \frac{12}{5}$
(2 solution(s))

4. Graph

Each line represents the function of one side of the equation:
$y = | - 3 x + 5 |$
$y = | - 2 x + 7 |$
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