X+y=3
x=3-y
(3-y)^4+y^4=17
81-108y+57y²-12y³+y^4+2y^4-17=0
2y^4-12y³+54y²-108y+64=0
2y³(y-1)-10y²(y-1)+44y(y-1)-64(y-1)=0
(y-1)(2y²-10y²+44y-64)=0
(y-1)[2y²(y-2)-6y(y-2)+32(y-2)]=0
(y-1)(y-2)(2y²-6y+32)=0
y-1=0
y=1⇒x=3-1=2
y-2=0⇒x=3-2=1
2y²-6y+32=0
D=36-256=-220<0 нет решения<br>Ответ (1;2);(2;1)