1)а)у-10
б)(х+8)^2
в)2(х*5)
2)а)(3+х)^2=9+6х+х^2
б)(4х-1)^2=16х^2-8х+1
в)(2х+3у)^2=4х^2+12ху+9у^2
г)(у^2+2)^2=у^4+4у^2+4
3)а)х^2+4х+4=(х+2)^2
б)25х^2-10ху+у^2=(5х-у)^2
в)49х^2-42ху+9у^2=(7х-3у)^2
4)а)(7х-2)^2+28х=49х^2-28х+4+28х=49х^2+4
б)27х^2-3(3х-1)^2=27х^2-3(9х^2-6х+1)=
27х^2-27х^2+18х-3=18х-3
5)х(х-4)-(х-8)^2=х^2-4х-(х^2-16х+64)=
х^2-4х-х^2+16х-64=12х-64
х=0,5
12*0,5-64=6-64=-58