Simplify 9√3 over √5

Simply this means to get the square root sign off the bottom, or off the denominator.
Think of some number to multiply times the bottom, that will make a perfect square root out of it, and add the same time, multiply the number times the top.; such as:
9xsquareroot of 3 over squareroot of 5.
Multiply the top and bottom by squareroot of 5, then you can finish the answer.
Good luck.