Inequality
A comparison of quantities that have different values. There are four ways to express inequalities: less than (<), less than or equal to (<=), greater than (>), or greater than or equal to (=>). Can be manipulated in the same way as equations with one exception: when multiplying or dividing by a negative number, the inequality sign flips.
Compound Inequality
More than two inequalities strung together. For example, 2 < x < 5 is a compound inequality, as is a < b < c < d. When manipulating, the same operations must be done to every term in the inequality. For example, given x < y + 2 < 2x, if we subtract 2 from the middle term to get y by itself, we must also subtract 2 from the first and third terms: x - 2 < y < 2x – 2.
