∫x51+x323dx is equal to
18u8/3−15u5/3+C,u=1+x3
38u8/3−35u5/3+C,u=1+x3
−38u8/3+35u5/3+C,u=1+x3
−18u8/3+15u5/3+C,u−1+x3
Put 1+x3=t3⇒x2dx=t2dt
∫x51+x323dx=∫t3-1t4dt
=t88−t55+C=181+x38/3−151+x35/3+C.