To solve this, you need to evaluate the function at f(1), which just means that you have to plug in 1 for any x you see in the equation. For example, here f(1) = 2(1) + 2 which simplifies to 4. Next find f(5). By doing the same process you will find that this is 12. The problem asks for f(1) + f(5) so by putting those values in you will get 4+12=16. Hope this helps! :)