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

Question

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

Answer 1

(х-y)(х+y)=x^2-y^2

(x-2y)^2=x^2-4xy+4y^2

x^2-y^2-x^2+4xy-4y^2=-5y^2+4xy

Answer 2

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

((X-y)-(x-2y))((X-y)+(x-2y)

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

(-y+2y)(2x-3y)

Y(2x-3y)

2xy-3y^2