9х²-3х+1+27х³+9х²+27х³=18х²-3х+1+54х³=18х²(1+3х)-(3х-1)

(3х+х²+6+2х)(3-х)+(х³+2х²)=(5х+х²+6)(3-х)+(х³+2х²)=(15х-5х²+3х²-х³+18-6х)+(х³+2х²)=9х-2х²-х³+18+х³+2х²=9х+18=9(х+2)

х²+8х+16-9(х²-8х+16)=х²+8х+16-9х²+72х-144=-8х²+80х+16=8(х²+10х+2)