Factorization x (y + 2) - x-y-1
x(y+2)-x-y-1=(x-1)(y+1)
Factorization: x ^ 2 (y ^ 2-1) + (1-y ^ 2)
^2 is quadratic
Original formula = x ^ 2 (y ^ 2-1) - (y ^ 2-1)
=(y^2-1)(x^2-1)
=(y+1)(y-1)(x+1)(x-1)
-99 plus 100 minus 97 plus 98 minus 95 plus 96. What's one minus two
50