Делим все на 8.
x^2-3x+2.25=0
x1+x2=3
x1*x2=2.25
x1=1.5 x2=1.5
x=1.5
D=25+96=121
x1,2= -5+-11/12
х1=-5+11/12=6/12=1/2
х2=-5-11/12=-16/12=-4/3=-1 1/3
(х-1/2)(х+1 1/3)
E(y)∈3*[-1;1]-2=[-3;3]-2=[-5;1]
x^3+y^3=9
x+y=3
(x+y)(x^2-xy+y^2)=9
x+y=3
(x+y)(x^2-xy+y^2)/(x+y)=9/3
x^2-xy+y^2=3
x+y=3 =>x=3-y
(3-y)^2-(3-y)y+y^2=3
9-6y+y^2-3y+y^2+y^2=3
3y^2-9y+6=0
y^2-3y+2=0
(y-1)(y-2)=0
y=1; y=2
x=3-1=2
x=3-2=1
Ответ: (2;1);(1;2)