Which substitution simplifies the integral ∫dxx(1+x)\int \frac{dx}{\sqrt{x}(1+x)}∫x(1+x)dx?
u=xu = xu=x
u=xu = \sqrt{x}u=x
u=1+xu = 1+xu=1+x
u=x+1u = \sqrt{x} + 1u=x+1