Answer:
x = 10
Explanation:
To isolate the variable (x) you would first write out x - 3 = 7. Now to make x on its own we have to get rid of the -3 so to do that we would add the reciprocal of -3 (or the opposite) which is +3. x - 3 + 3 = 7 + 3 or x = 10.