I am having trouble with this problem also

Question

derivative

differentiate

f(x)=(3-x)^4(x+5)^3

so far I have 4(3-x(x+5)^3+3(x+5)(3-x)

Not quite right.
Treat it as d/dx[u(x) + v(x)]
= u dv/dx + v du/dx
u(x) = (3-x)^4 v(x) = (x+5)^3
du/dx = -4(3-x))^3 (using the chain rule)
dv/dx = 3(x+5)^2

[4(3-x)^3*(-1)(x+5)^3] + [3(x+5)^2*(3-x)^4]