Question

Упростить:
(x+2y)(x-y)+y(y-x)

Answer 1

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

Answer 2

(x+2y)(x-y)+y(y-x)=(х*х+х*у+2у*х+2у*у)+у*у+у*х=х^2+ху+2ху+2у^2+у^2+ху=х^2+4ху+3у^2