解
(y-1)²+2y(1-y)=0
(y-1)²-2y(y-1)=0
(y-1)(y-1-2y)=0
(y-1)(-y-1)=0
∴y=1,y=-1
(1-x)²=0.64
1-x=-0.8或1-x=0.8
∴x=1.8或x=0.2