(m-3)x+5=0
x=-5/(m-3)
又|M|=x-2
所以|M|=-5/(m-3)-2
当m>0时,有m=-5/(m-3)-2
(m+2)(m-3)=-5
m^2-m-6+5=0
m^2-m-1=0
m=(1+根号5)/2
当m