Question

factorize 100 - a^2 - b^2 - 2ab​

Answer 1

This can be written as 100 - ( a^2 +b^2 + 2ab)

and we know that (a + b) ^2 = a^2 +b^2 + 2ab

so 10^2 - (a+b)^2

or (10 + a + b) ( 10 - a - b)

Since a^2 - b^2 = (a+ b)( a - b)