解方程(y-1)²+2y(1-y)=0 （1-x）²=0.64

解方程(y-1)²+2y(1-y)=0 （1-x）²=0.64
解方程(y-1)²+2y(1-y)=0 （1-x）²=0.64

解方程(y-1)²+2y(1-y)=0 （1-x）²=0.64
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

y2-2y+1+2y-2y2=0
1-y2=0
y=+-1
1-x=+-0.8
x=0.2,x=1.8

①(y-1)²+2y(1-y)=0
y²-2y+1+2y-2y²=0
y²=1
y=1或y-1
②（1-x）²=0.64
1-x=0.8或1-x=-0.8
x=0.2或x=1.8