Factories:
x2 – xz + xy – yz
Let’s first arrange the terms in a suitable form;
= x2 + xy – xz – yz
= (x2 + xy) – (xz + yz)
= x(x + y) – z(x + y)
= (x + y)(x – z)
So we get,
x2 – xz + xy – yz = (x + y)(x – z)