Let u = ln(x) and dv/dx = x
Thus du/dx = 1/x and v = x2/2
Using the formula:
Integral of udv/dx = uv - Integral of v*du/dx
This becomes: Integral of x*ln(x) = (x2ln(x))/2 - Integral of x/2
Completing the integral on the RHS gives the answer to the question: (x2ln(x))/2 - x2/4