so this is so confusing i got lost.

The Question:

A cup of cofee placed in a room cools from 160F to 150F in one minute. if the room temperature is 65F, Find the temperature in ten minutes.

so the formula for this is

(change in temperature over one time period) = A ( temperature at the beginning of the - room temperature time period)

150F - 160F = A (160 - 65)

-10F = A(105)

A = -1050F ???what this is where i got lost help please!