Factories:

x2 – xz + xy – yz

Let’s first arrange the terms in a suitable form;


x2 – xz + xy – yz


= 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)


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