∫ x(1 + lnx) dx= ∫ (1 + lnx) d(x²/2)= (1/2)x²(1 + lnx) - (1/2)∫ x² d(1 + lnx)= x²/2 + (1/2)x²lnx - (1/2)∫ x² • 1/x dx= x²/2 + (1/2)x²lnx - (1/2)∫ x d...