You can put this solution on YOUR website! Your 3(-x) makes no sense. I will assume that you meant to type x^(-3).
Using the rules of negative exponents, x^(-3) becomes 1/x^3.
We now have the problem 1/(x^3) divided by x^2.
Using the rules of division of fractions, the problem becomes
1/(x^3) times 1/x^2 = 1/x^5