原等式即：x^2-2x+1+y^2-y+1/4=0亦即(x-1)^2+(y-1/2)^2=0由于左边两个加数都为非负数,所以x-1=0,y-1/2=0所以x=1,y=1/2y-x = 1/2 - 1 = - 2分之1 施主,我看你骨骼清奇,器宇轩昂,且有慧根,乃是万中无一的武林奇才.潜心...