Номер1
1)9+6х+х^2=(3+х)^2;
2)(2х-0,5)^2=4х^2-2х+0,25;
3)9х^2-24ху+16у^2=(3х-4у)^2;
4)(х^3-у^4)^2=х^6-2х^3у^4+у^8;
5)(2х-1)^2=4х^2-4х+1;
6)х^4+10х2+25=(х^2+5)^2;
7)х^2+18х+81=(х+9)^2;
8)(-5х+6у)^2=(6у-5х)^2=36у^2-60ху+25х^2.
номер2
а)(7х-2)^2+28х=49х^2-28х+4+28х=49х^2+4;
б)(6х+5у)^2-60ху=36х^2+60ху+25у^2-60х=36х^2+25у^2