okay, would it be 2x+4?!?!?!?
No, no, no. You've found the common denominator. Now you have to get the common denominator. You do that by multiplying fractions by fancy ways of writing 1 in order to obtain the common denominator in each denominator. Let me illustrate:
So far, you would agree I haven't changed anything, right? I've multiplied each fraction by something that's equal to 1 (the fractions that are in parentheses). But I've chosen those numbers carefully so that when I multiply out the denominators, I'll get the common denominator that I need. Thus, the next step is to multiply out the fractions, which you can do the way you want to do it:
Do you see how this is done? And do you know what the next steps are?