(a+3)²= (2a-1)³= (3x+4)²-9x2= (7x-1)²= (x+2)³= (2x+3y)²-6xy-9y2=

1) (а+3)^2= а^2+6а+9;
2) (2а-1)^3= 8а^3-12а^2+6а-1;
3) (3х+4)^2-9х^2= 9х^2+24х+16-9х^2=
24х+16= 8(3х+2);
4) (7х-1)^2= 49х^2-14х+1;
5) (х+2)^3= х^3+6х^2+12х+8;
6) (2х+3у)^2-6ху-9у^2=
4х^2+12ху+9у^2-6ху-9у^2=
4х^2+6ху= 2х(2х+3у).