直线:x+2y-3=0与圆：x^2+y^2+x-6y+m=0有两个不同的交点A,B,O为坐标原点,若OA垂

若OA垂OB,求m的数值
假设A(X1,Y1)B(X2,Y2)
则：KOA*KOB=Y1Y2/X1X2=-1
X1X2+Y1Y2=0
x^2+y^2+x-6y+m=0
5Y^2-20Y+12+m=0,y1y2=(12+m)/5
5x^2-10x+4m-27=0,x1x2=(4m-27)/5
(12+m)/5+(4m-27)/5=0
m=3