Question

factorise the following
x(x+z)-y(y+z)

Answer 1

x²+zx-y²-yz
=x²-y²+zx-zy
=(x+y)(x-y)+z(x-y)
=(x-y)(x+y+z)

Answer 2

x(x+z)-y(y+z)
x2+xz-yz-y2
(x2-y2)+(xz-yz)
(x)2-(y)2+(xz-yz)
(x)2-(y)2+z(x-y)
(x+y)(x-y)+z(x-y)
(x-y)(x+y+z)