im trying to do this but i dont know where to start also its precalculus its due in a few hours

Question

A roasted turkey is taken from an oven when its temperature has reached 185 Fahrenheit and is placed on a table in a room where the temperature is 75 Fahrenheit. Give answers accurate to at least 2 decimal places.

(a) If the temperature of the turkey is 149 Fahrenheit after half an hour, what is its temperature after 45 minutes?

____   Fahrenheit

(b) When will the turkey cool to 100 Fahrenheit?

____   hours.

Answer 1

Let T = at + b, t is time and T is temperature in Fahrenheit and t is time in hours. We have 2 points (0, 185) and (0.5, 149) to get a and b: 185 = b; 149 = 0.5a + 185; a = - 72.

T = - 72t + 185.

(a) If t = 45min = 0.75 hour then T = - 72·0.75 + 185 = 131°F

(b) If T = 100°Fthen 100 = - 72t + 185; t = 85/72 hours = 70.83 min