# Inequalities » What is an inequality?

An inequality is a sort of equation. With an equation you calculate when two formulas are equal. With an inequality you calculate when one of the formulas is less (or greater) than the other formula. This of course has everything to do with the point(s) of intersection of the two formulas.

You have to know the meaning of the different signs being used.

If necessary, check domain and range for theory about intervals.

*Examples*

x + 5 > 4x + 7 | Check linear inequalities. |

3x + 7 < 20x | |

7x^{2} + 5 ≥ 4x | Check quadratic inequalities. |

2x^{2} – 8x < x^{2} – 7 |