Hi! This is a question from integrals in calculus, however, i really do not get how to solve it.

You are driving your car at a comfortable speed of 18 m/s (≈65 km/h) when
a confused pedestrian jumps onto the road. You hit the brakes and the car decelerates at a constant rate of 6m/sec^2.
(a) Find the formula for the velocity v(t) of the car t seconds after the brakes are applied.
(b) How long will it take before the car comes to a standstill?
(c) Find the formula for the distance d(t) that the car travels t seconds after the brakes are
applied.
(d) What distance will the car have travelled from the point that the brakes were applied?

Thank you so much!

(a) v = 18-6t

(b) solve for v=0
(c) d(t) = ∫18-6t dt = 18t - 3t^2
(d) evaluate (c) at the value from (b)