已知x^2+y^2-8x+12y+52=0 ,求1/2x-1/x-y(x-y/2x-x^2+y^2)

问题描述:

已知x^2+y^2-8x+12y+52=0 ,求1/2x-1/x-y(x-y/2x-x^2+y^2)

1/2x-1/x-y(x-y/2x-x^2+y^2)不是=1/x-y(x-y/2x-x^2+y^2)吗
x^2+y^2-8x+12y+52=0=(X-4)^2+(y+6)^2
得x=4 y=-6
代入就行了