d) (x – y)^2 – (y – z)^2;
d) (x – y)2 – (y – z)2;
d) (x – y)2 – (y – z)2
= (x ‒ y + y ‒ z)(x ‒ y ‒ y + z)
= (x ‒ z)(x ‒ 2y + z).