Question

разложите на множители
2(x+y)(x-y)-(x+y)^2

Answer 1

=(х+у)(2(х-у)-(х+у))=(х+у)(2х-2у-х-у)=(х+у)(х-3у)

Answer 2

2(x^2-y^2)-(x^2+2xy+y^2)=2x^2-2y^2-2xy-x^2-y^2=x^2-3y^2-2xy