Hey there!
To find a solution that would satisfy the value of x, the first thing you must do is to first solve for x. To solve x-7=35, you must add 7 to both sides to isolate x. This should result in x=42.
When you look at the answer choices given, notice that choice C is the solution for x, 42.
Therefore, your answer would be C. 42.
To check if this is correct, you can plug 42 back into the equation x-7=35 to see if you get a true statement:
42-7=35
35=35
Hope this helps!