Question

9. Add : x² - y2 - 1, y2 - 1 - x2​

Answer 1

Answer:

-2

Step-by-step explanation:

x²-y²-1,y²-1-x²

x²-y²-1+y²-1-x²

x²-x²-y²+y²-1-1

x²and x² will be cut

-y²and +y² will be cut

-1-1= -2