x/x^3+y^3 , x/x+y

Question

The LCD is

Answer 1

x^3 + y^3 = (x + y)(x2 - xy + y2)

The lowest common denominator is therefore x^3 + y^3. (x+y) is a factor of both denominators

x/(x+y) = [x(x^2 -xy + y^2)]/(x^3 + y^3)