x ln(3 + x) dx

Answer 1

assuming you want to integrate, let
u=ln(3+x)
dv = x dx

du = 1/(3+x) dx
v = x^2/2

∫u dv = uv - ∫v du
∫x ln(3+x) dx = x^2/2 ln(3+x) - 1/2 ∫x^2/(3+x) dx

Now just divide, and you will have easy stuff left.