过A
3=k/(-2)
k=-6
则m=-6/3=-2
代入y=ax+b
3=-2a+b
-2=3a+b
相减
5a=-5
a=-1
b=2a+3=1
所以是-6/(x-6)-1/(x+1)=0
-6/(x-6)=1/(x+1)
-6x-6=x-6
x=0