Enter an equation or problem

Camera input is not recognized!

Solution - Absolute value equations

Exact form:

v = 17, \frac{7}{5}

v=17 , \frac{7}{5}

Mixed number form:

v = 17, 1 \frac{2}{5}

v=17 , 1\frac{2}{5}

Decimal form:

v = 17, 1.4

v=17 , 1.4

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
$3 | v - 4 | = | 2 v + 5 |$
without the absolute value bars:

$\| x \| = \| y \|$	$3 \| v - 4 \| = \| 2 v + 5 \|$
$x = + y$	$3 (v - 4) = (2 v + 5)$
$x = - y$	$3 (v - 4) = - (2 v + 5)$
$+ x = y$	$3 (v - 4) = (2 v + 5)$
$- x = y$	$3 (- (v - 4)) = (2 v + 5)$

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:

$\| x \| = \| y \|$	$3 \| v - 4 \| = \| 2 v + 5 \|$
$x = + y$ , $+ x = y$	$3 (v - 4) = (2 v + 5)$
$x = - y$ , $- x = y$	$3 (v - 4) = - (2 v + 5)$

2. Solve the two equations for v

9 additional steps

$3 \cdot (v - 4) = (2 v + 5)$

Expand the parentheses:

$3 v + 3 \cdot - 4 = (2 v + 5)$

Simplify the arithmetic:

$3 v - 12 = (2 v + 5)$

Subtract from both sides:

$(3 v - 12) - 2 v = (2 v + 5) - 2 v$

Group like terms:

$(3 v - 2 v) - 12 = (2 v + 5) - 2 v$

Simplify the arithmetic:

$v - 12 = (2 v + 5) - 2 v$

Group like terms:

$v - 12 = (2 v - 2 v) + 5$

Simplify the arithmetic:

$v - 12 = 5$

Add to both sides:

$(v - 12) + 12 = 5 + 12$

Simplify the arithmetic:

$v = 5 + 12$

Simplify the arithmetic:

$v = 17$

12 additional steps

$3 \cdot (v - 4) = - (2 v + 5)$

Expand the parentheses:

$3 v + 3 \cdot - 4 = - (2 v + 5)$

Simplify the arithmetic:

$3 v - 12 = - (2 v + 5)$

Expand the parentheses:

$3 v - 12 = - 2 v - 5$

Add to both sides:

$(3 v - 12) + 2 v = (- 2 v - 5) + 2 v$

Group like terms:

$(3 v + 2 v) - 12 = (- 2 v - 5) + 2 v$

Simplify the arithmetic:

$5 v - 12 = (- 2 v - 5) + 2 v$

Group like terms:

$5 v - 12 = (- 2 v + 2 v) - 5$

Simplify the arithmetic:

$5 v - 12 = - 5$

Add to both sides:

$(5 v - 12) + 12 = - 5 + 12$

Simplify the arithmetic:

$5 v = - 5 + 12$

Simplify the arithmetic:

$5 v = 7$

Divide both sides by :

$\frac{(5 v)}{5} = \frac{7}{5}$

Simplify the fraction:

$v = \frac{7}{5}$

3. List the solutions

$v = 17, \frac{7}{5}$
(2 solution(s))

4. Graph

Each line represents the function of one side of the equation:
$y = 3 | v - 4 |$
$y = | 2 v + 5 |$
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 v

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 v

3. List the solutions

4. Graph

Why learn this

Terms and topics

Related links

Latest Related Drills Solved