1)
(2х-3)(4х^2+6х+9)-8х^2=2,7х
8х^3-27-8х^3=2,7х
2,7х=-27
х=-10
2)
(3+4х)(16х^2-12х+9)-64х^3=-10х
27+64х^3-64х^3=-10х
-10х=27
х=-2,7
3)
(5-2х)(4х^2+10х+25)=2,5х
125-8х^3=2,5х-8х^3
2,5х=125
х=50
4)
(6-5х)(36+30х+25х^2)=108х-152х^3
216-125х^3=108х-125х^3
108х=216
х=2