What is the minimum work needed to push a 1075 kg car 230 m up along a 17.5° incline?

(a) Ignore friction.
(b) Assume the effective coefficient of friction retarding the car is 0.30?

I just found out for part a that you would do:

1075*9.8*230*sin(17.5)
which would then equal:
726915

I still need help with part b though.