Evaluate the integral by making the given substitution.x2x3+16dx, u = x3+16Step 1We know that ifu = f(x),thendu = f(x) dx.Therefore, ifu = x3+16,thendu =$$3x2dx.Step 2Ifu = x3+16is substituted intox2x3+16dx,then we havex2(u)12 dx=u12 x2 dx.We must also convertx2 dxinto an expression involving u.We know thatdu =3x2 dx,sox2 dx =du.