For those of you who got y=9.5x, and you don’t know why there is a -112. That is because the question is asking for an equation specifically for cruising time. That means you have to subtract a certain distance which is 112 km that it wasn’t in cruising time. The parameters are [32, to infinity) for the domain. The point where the plane comes into cruising time is 32, 192. You wouldn’t start at one minute because it is not in the domain for cruising time.