Question

The temperature is 45°F. The temperature will decrease by 2°F each hour. Let h be the number of hours. When will the temperature be below 32°F?

Answer 1

Answer: 45 - 2h < 32

Explanation:

1) The temperature is 45°F. => starting temperature T = 45

2) The temperature will decrease by 2°F each hour. Let h be the number of hours.

=> T = 45 - 2h

3) When will the temperature be below 32°F?

=> T < 32

=> 45 - 2h < 32

Answer: the inequality is 45 - 2h < 32

4) You can solve it to know how many hours have to elapse:

45 - 2h - 45 < 32 - 45

- 2h < - 7

2h > 7

h > 7/2

h > 3.5

Therefore, it has to elapse more than 3 and a half hours.