i have the fraction

f(x) = (x-8)/(x+2)(2x-1)

part (a) was to to express that into a partial fraction n i got

2/(x+2) - 3/(2x-1)

part (b) says

Find f'(0)

my question for part (b) is do i differentiate the original fraction or the partial fraction i found in part (a)???