Question

у(7у+4х)-(2х+у)^2 упростите выражение

Answer 1

7y^2+4xy-4x^2-2xy-2xy-y^2=-4x^2+6y^2

Answer 2

7y^2+4xy-(4x^2+4xy+y^2)=
7y^2+4xy-4x^2-4xy-y^2=
6y^2-4x^2=2(3y^2-2x^2)