A) = (x+1)² - (y-2)² = (x+1+y-2)(x+1-y+2)= (x+y-1)(x-y+3)
B) = 9a²- (x-3)² = (3a-x+3)(3a +x-3)
C) = (x-6)² - (y²+2yz+z²) = (x-6)² - (y+z)² = (x-6-y-z)(x-6+y+z)=(x-y-z-6)(x+y+z-6)
D) =(x+√5)² - (y-√2)² = (x+√5 -y+√2)(x+√5+y -√2) =(x-y+√5+√2)(x+y +√5-√2)