Question

X²-Y²-1+y²-1-X²+1-X²-Y²​

Answer 1

Answer:

- x² - y² - 1

Step-by-step explanation:

x² - y² - 1 + y² - 1 - x² + 1 - x² - y²

= x² - x² - x² + y² - y² - y² - 1 - 1 + 1

= x² - 2x² + y² - 2y² - 2 + 1

= - x² - y² - 1