Ristermit 21/10/2013 (x+1)² - (y+1)² =x² + 2x+1 - (y² + 2y +1) =x² + 2x + 1 - y² - 2y - 1=x² + 2x - y² - 2y =x(x + 2) - y(y+2) =(x -y) (x + y + 2)
Ristermit
(x+1)² - (y+1)² =
x² + 2x+1 - (y² + 2y +1) =
x² + 2x + 1 - y² - 2y - 1=
x² + 2x - y² - 2y =
x(x + 2) - y(y+2) =
(x -y) (x + y + 2)