99a^2+99b^2-202ab. factorise?

Answer 1

99a^2+99b^2-202ab

Step 1: Reorder:
99a^2 - 202ab + 99b^2

Step 2: See if you can factor it.
The first instinct is to factor it as:
(9a - 11b)(11a - 9b), but that would equal 99a^2 - 198ab + 99b^2.

There is no way to factor 99a^2 - 202ab + 99b^2, because if you use the other factors of 99, you go over -202.

Answer 2

reorder to 99a^2 -202ab +99b^2
it's easier to see...(9a - 11b) (11a - 9b)