Question

Factorise: x²- 1 - 2y - y²​

Answer 1

Answer:

(x+y+1)(x-y-1)

Step-by-step explanation:

x² - 1 - 2y - y²

= x² - y² - 2y - 1

= x² - ( y² + 2y + 1 )

= x² - ( y + 1 )²

= [ x + ( y + 1 ) ] × [ x - ( y + 1 ) ]

= [ x + y + 1 ] × [ x - y - 1 ]