A thermometer reading 70 F is placed in an over pre-heated to a constant temperature. through a glass window in the over door, an observer records that the thermometer reads 110 F after 1/2 minute and 145 F after 1 minute. so how hot is the over..?

ok i have the formula for the problem,

dT/dt = k(T-Tm)

I also know that the initial temp is 70 F

I guess my problem starts with, not knowing how to separate the variables...any help would be appreciated.

thanks in advance..