Diketahui f(x)= (x-4)(2x-1) dan f'(p)=15. Nilai f(p)= A.22 B. 15 C.8 D.6 E.2 Mohon bantuannya serta caranya

f(x) = 2x^2 - x - 8x + 4
f(x) = 2x^2 -9x + 4
f'(p) = 4p - 9 = 15
4p = 15 + 9
4p = 24
p = 6

f(p) = 2p^2 -9p + 4
= 2(6)^2 - 9(6) + 4
= 2(36) - 54 + 4
= 72 - 54 + 4
= 22