Question

As arctic air moved into a region where the temperature was originally 17°C, the temperature began falling at a steady rate of 2°C per hour. What was the temperature after 9 hours?

Answer 1

First you would multiply your hours, 9, by how fast the temperature is dropping, -2 ( because it is dropping, your number would be a negative). 9 x -2 = -18.
Next add 17 + -18 to get -1. -1°C is your answer.