103^2-102^2
The property that applies here is a^2-b^2 = (a+b)(a-b)
so the answer is 103^2-102^2=(102+103)*(103-102)= numerically it is 205( as 103+102 = 205 and 103-102 = 1.....so 205*1 = 205)
The thing is that usually the factorization ends at (102+103)(102-103) ......