x+y=9
(x+y)^2=9^2
x^2+2xy+y^2=81
a) 4(x^2+y^2+2xy)=4*81=324
б)13+(x2+y2+2xy)=13+81=94
в)10+(-2xy-x2-y2)=10+(-81)=-71
г)19+(-9(x^2+y^2+2xy))=19+(-9*81)=710
x+y=9
(x+y)^2=9^2
x^2+2xy+y^2=81
a) 4(x^2+y^2+2xy)=4*81=324
б)13+(x2+y2+2xy)=13+81=94
в)10+(-2xy-x2-y2)=10+(-81)=-71
г)19+(-9(x^2+y^2+2xy))=19+(-9*81)=710