Question

Упростите выражение (2y-1)(1+4y+y^2)+(1-2y)(1+6y+y^2)+4y^2

Answer 1

$(2y-1)(1+4y+y^{2})-(2y-1)(1+6y+y^{2})+4y^{2}= \\ (2y-1)(1+4y+y^{2}-1-6y-y^{2})+4y^{2}=(2y-1)(-2y)+4y^{2}= \\ =-4y^{2}+2y+4y^{2}=2y$