Problem Solving

Hi guys,

I have a quick question that I am unsure about in terms of how variables are presented in questions:

Example:
If ab ≠ 0, does a = b?

(1) xa = xb
(2) x = x2


here does "ab" indicate "a" times "b" (3 x 4 so ab would be 12) or a 2 digit number "ab" (15 where a is 1 and b is 5).


I have seen "ab" in a few different questions where it represents each scenario. Or is it only a 2 digit number when they state - ab is a positive two digit integer? Can I assume it mean a times b unless it says otherwise?

Thanks.