Let me explain why i think that is the answer. First off, i turned the problem around so it was easier for me to solve.
I think that it stays '7 - x' because they arent like terms so you cant combine them, so i think that stays the same. Because i cant change that, i added '2 + 9' and i got 11. I then took the 11 and subtracted it by itself and the 19. Because i subtracted it by itself, the 11 canceled out and i got 8 from the 19 - 11. Like i said, i couldnt do anything with the ' 7 - x' i ended up with 7 - x = 8.
