∫x^3/(x+1)dx
∫[(x³+1)-1]/(x+1)dx
=∫[x²-x+1-1/(x+1)]dx
=x³/3-x²/2+x-ln(x+1)+c ∫x^3/(x+1)dx
∫[(x³+1)-1]/(x+1)dx
=∫[x²-x+1-1/(x+1)]dx
=x³/3-x²/2+x-ln(x+1)+c