1)2x^2-y=2 2x^2-y=2 2(y+1)^2-y=2 2(y^2+2y+1)-y=2 2y^2+4y+2-y=2
x-y=1 x=y+1 2y^2+3y=0
y(2y+3)=0
y=0 y=-1,5
y=0 y=-1,5
x=0+1=1 х=-1,5+1=-0,5
Ответ:у1=0,х1=1,у2=-1,5,х2=-0,5
2)xy=15 x=15/y 2(15/y)-y=7 30/2y-y=7 30/2y-y-7=0 30/2y-2/2y-14y/2y=0
2x-y=7 2x-y=7 28-14y=0
-14y=-28
14y=28
y=2
y=2
x=15/2=7,5
Ответ:у=2,х=7,5