Question

f(x)=4x+5/(x+2)(x-4)x

Answer 1

$f`(x)=(4x^3-8x^2-32x-12x^3-16x^2-32x+15x^2-20x-40)/$$(x+2)^2(x-4)^2x^2=(-8x^3-9x^2-84x-40)/(x+2^2(x-4)^2x^2$