Answer:
the first one should be 2 because
if you put 2 it would look like this:
7x + 2 = 7x + 2
and if you answer it or try to simplify
7x + 2 = 7x + 2 or 7x + 2 = 7x + 2
- 2 - 2 -7x -7x
7x = 7x 2 = 2
/7 /7
x = x
and for the second one could be any number but 2
to prove this lets choose 5
and now to solve:
7x + 2 = 7x + 5 or 7x + 2 = 7x + 5
-7x -7x - 2 - 2
2 ≠ 5 7x = 7x + 3
-7x -7x
0 ≠ 3