Question

已知x*2+y*2-8x+10y+41=0

Answer 1

x^2+y^2-8x+10y+41=0

(x^2-8x+16)+(y^2+10y+25)=0

(x-4)^2+(y+5)^2=0

x-4=0,x=4

y+5=0,y=5

(x/y)-(y/x)

=(x^2-y^2)/(xy)

=(16-25)/20

=-9/20

2.(y+1)/(x+1)+(x+1)/(y+1)

=[...