You are driving on the highway, and you come to a steep downhill section. as you roll down the hill, you take your foot off the gas pedal. you can ignore friction, but you can't ignore air resistance.
identify all the forces acting on the car.

Explanation: Here you know that:

The car is in downhill (so the gravitational force accelerates the car downhill)

we can ignore the friction (so there is no force of friction)

We can not ignore the air resistance (so whe have force of air resistance that is oposite to the direction in which the car moves)

You take the foot of the gas pedal (so there is no intrinsic acceleration of the car)

then the only two forces are the component of the gravitational force in the downhill direction, and the force of the air resistance that is in opposite direction than the gravitational force.

attach the statements so i can answer : )