Plz factoriz (x+y)^2-x-y

plz xpln

(x + y)^2 - x - y

(x + y)^2 - (x + y)

let
x + y = a

a^2 - a

a(a - 1)

sub back in

(x + y)(x + y - 1)

(x+y)^2 = x^2 + y^2 - 2xy

so subtracting xy gives

x^2 + y^2 - xy

this doesn't easily completely factorise so I'll partially factorise it by pulling x out.

x(x-y) + y^2

(x+y)^2-x-y = (x+y)^2-(x+y) = (x+y)(x+y-1)