1-a^2-b^2+2ab 因式分解
问题描述:
1-a^2-b^2+2ab 因式分解
答
= 1 - (a^2 + b^2 - 2 a b)
= 1 - (a - b)^2
= [1 + (a - b)] [1 - (a - b)]
= ( 1 + a - b) (1 - a + b)