Question

Define a variable, write an inequality, and solve each problem.

A number decreased by 7 is at least 15.

Answer 1

Answer: x is greater than it equal to 22

Explanation:

Answer 2

x = some unknown number

x-7 = decrease the unknown number by 7

The "is at least 15" part means x-7 = 15 or x-7 > 15

That condenses to x-7 ≥ 15

Add 7 to both sides to isolate x.

x-7 ≥ 15

x-7+7 ≥ 15+7

x ≥ 22

The unknown number is 22 or larger.