# math

posted by
**Matt** on
.

Please help me on this calculus question. I am getting the wrong diff. equation and so my answers to the remaining parts are wrong.

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A thermometer reading 85 degress outside is brought into a room with a constant temperature of 72 degrees. The rate of change, dT/dt is directly proportional to the difference between the temperatures.

A. Write the differential equation

B. Solve the diff. equation that you wrote subject to the fact that when t=0, the thermometer was 85 degrees

C. In 2 minutes the temperature is 83 degrees. Find K (proportionality constant)

D. How long till the temperature drops to 75 degrees