а) (х²+1)²-9х²= (х²+1+3х)(х²+1-3х)=
= (х²+3х+1)(х²-3х+1)
б) (3х+1)²-(4х+3)²=
=(3х+1+4х+3)*(3х+1-4х-3)=
=(7х+4)(-х-2)= -(х+2)(7х+4)
а) (х²+1)²-9х²= (х²+1+3х)(х²+1-3х)=
= (х²+3х+1)(х²-3х+1)
б) (3х+1)²-(4х+3)²=
=(3х+1+4х+3)*(3х+1-4х-3)=
=(7х+4)(-х-2)= -(х+2)(7х+4)