It is pretty easy to solve this equation, given that the denominator is the same of either side (x + 5). You don't even need the brackets.
So:
4x+2/x+5 + 3x+1/x+5 = 4x+2+3x+1/x+5 = 7x + 3/x+5
The correct answer is 7x + 3 / x + 5.
It's the same as if you were adding for example 2/3 and 6/3 - since the denominator is the same, you should just add 2 and 6 and get 8/3.