(1-2х)(4х+2х+1)=8(1-х2)(х+2)
4х+2х+1-8х^2-4х^2-2х=(8-16х)(х+2) 4х+2х+1-8х^2-4х^2-2х=8х+16-16х^2-32х 28х+4х^2=15