16. When Laura finishes cooking, her oven temperature is 400°F. If her oven cools at a rate of

3.25°F per minute, how many minutes will it take

for her oven to reach 75°F? Enter your response in

the gridded area.

DW

Her oven will cool to 75°F in 100 minutes, or 1 hour 40 minutes.

Step-by-step explanation:

Let T (t) represent the oven temperature, and t the time in minutes.

Then:

T (t) = 400°F - (3.25°F/min) t

Find the time, t, at which T (t) will = 75°F:

400°F - (3.25°F/min) t = 75°F

Subtracting 75°F from both sides, we get:

(3.25°F/min) t = 325°F.

Dividing both sides by (3.25°F/min) yields:

t = 100 minutes.

Her oven will cool to 75°F in 100 minutes, or 1 hour 40 minutes.