Answer:
T(h) = 20 - 3h
Step-by-step explanation:
We are told that for every km you go up, the temp goes down 3°.
Let's say you go up 1km, then the temp should be 17°. We can easily represent it by the equation: T(h) = 20 - 3h
If we go up 1km: T(1) = 20 - 3*(1) = 20 - 3 = 17°
If we go up 2km: T(2) = 20 - 3*(2) = 20 - 6 = 14°
If we go up 3km: T(3) = 20 - 3*(3) = 20 - 9 = 11°