Equations with Absolute Values

Equations = One or no solution.
Inequalities = Multiple solutions.
Equations with Absolute Values = 2 solutions (+ and -).

Absolute value:
http://www.mathsisfun.com/numbers/absolute-value.html

Absolute value in Algebra:
http://www.mathsisfun.com/algebra/absolute-value-solving.html

Example: how to solve an absolute value on an equation:
https://www.khanacademy.org/math/algebra/solving-linear-equations-and-inequalities/absolute-value-equations/v/absolute-value-equation-example