Your first instinct might be to go ahead and add the x terms together, BUT this would be a bad thing to do! You cannot combine the x2 and 2x, because the first term has an exponent (2) and the second one does not have an exponent; therefore, you cannot add them together!
Not sure if you mean multiplying or adding by "combine". But generally the rule of thumb with exponents is when you are adding and they are not like terms, you cannot combine the two terms together. So in other words, they would be left as x²+x. However, when you are multiplying you can add the exponents together. So, it will be like this: x²·x = x³
