Find the most general antiderivative of the function. UseCfor any needed constant. (Check your answer by differentiation.) (x>0)

I'm having trouble with this antiderivative

I've broken it up into 6/x^7 - 3/x^5 + 2 but im having trouble finding the derivative of the first two things.

I'm sorry if this is such a simple question I should know the answer to..