Yep, its known as a quadratic equation. Basically you need to find out what 9x^2 is made up of. It can only be 3x * 3x or 9x * x. Now you need to check what 25 can be made up of, either 5 * 5 or 25 * 1, you need to find the factors. Next is a bit of trial and error but you basically need to see how to get to 30 from the factors of 25. A quadratic equation always has double brackets, ( ) ( ). Now you need to play around with the numbers a bit and see what fits with what. The answer is (3x + 5) (3x + 5). Oh yeah depending on the symbol behind the 25, if its a +, in the bracket the signs will either be ++ or -- but if its a -, in the bracket the signs will be + and -. Hope i helped