Question

Lucy's goal for her cycling class at the gym is to burn 450 calories in one hour. The number of calories (c) she actually burns in one hour varies no more than 45 calories. Which inequality below represents this scenario?

A. |c - 450| ≤ 45

B. |c + 450| ≥ 45

C. |c - 45| ≤ 450

D. |c - 45| ≥ 450

Answer 1

That would mean that you want x≤475 and x≥425 calories!
The only inequality that fits this is A). Since |c - 450| ≤ 45 can be written as:

-45≤c-450≤45
Add 450 to both sides and get 425≤c≤475, which is the same as x≤475 and x≥425 calories =)