Step-by-step explanation:
look at the attachment......
Answer:
(x - 1)² - (y - 1)² has the form of a² - b² which is equal to (a - b)(a + b) where a = x-1 and b = y - 1
then
(x - 1)² - (y - 1)² = [(x - 1) - (y - 1)]×[(x - 1) + (y - 1)]
= [x - y]×[x + y - 2]
