For the first one, can't you write this : ? Is this what you mean in "not supposed to divide" ?
for the second problem
integration of (x^2+x^4/x)dx
=integration of (x^2/x+x^4/x)dx
=integration of (x+x^3)dx
=(x^2)/2+(x^4)/4 is the answer
here i'm considering instead of integration symbol as integration, i hope this steps are easy to calculuate.
step: first i divided by x
step: then integration with respect to x by using the formula of
integration of x^n dx= (x^n+1)/n+1