1)=6(х^2+2х+1)+2(х^3-1)-2(х^2+2х+1)(х+1)=
=6х^2+12х+6+2х^3-2-2х^3-4х^2-2х-2х^2-4х-2= 6х-2
2)=5х(х^2-6х+9)-5(х^2-2х+1)(х-1)+15х^2-60=
=5х^3-30х^2+45х-5х^3+10х^2-5х+5х^2-5х+5+15х^2-60=35х-60
3)=(х^2+4х+4)(х+2)-9х^3-6х^2-х+8х^3+1=
=х^3+4х^2+4х+2х^2+8х+8-9х^3-6х^2-х+8х^3+1=12х+9