0

An inequality is a mathematical relationship between two expressions and is represented using one of the following symbols:

 ≤: “less than or equal to,” 

<: “less than,” 

>: “greater than,”

 ≥: “greater than or equal to.” 

Note: Pay close attention to phrases such as “at most” (≤) or “at least” (≥).

Example: The sum of 8y and 3y is greater than 66.

    In symbols, 11y > 66

y > 6 Therefore y cannot be 6, it must be greater than 6.

Example: The sum of a number and 5 is at most 23.

  In symbols, n + 5 ≤ 23 “At most” means less than or equal to.

n ≤ 19

Example: The weight of the truck w, plus its load of two thousand pounds must be at least four thousand pounds. 

In symbol, w + 2000 ≥ 4000 “At least” means greater than or equal to.

w ≥ 2000

Example: Solve the inequality,

27 < x – 3

+3         +3

———————

30 < x

Example: Solve the equation,

– 10 + x > 30

+10        +10

——————- 

x > 40

Unit 3 Problems and Solutions 1