Originally Posted by
princess_21 why did it became like this? x^2 + xy - xz - xy - y^2 + yz + + zx + yz - z^2
i have the same answer but different way. how did you come up with that equation?
here's my solution
x^2-(y^2-2yz+z^2)
x^2-(y-z)^2
{x+(y-z)}{x-(y+z)
(x+y-z)(x-y+z)