m^2x=m(x-3)+3
m^2x-mx=3-3m
(m^2-m)x=3-3m
x=(3-3m)/(m^2-m)
x<=2,则有：
(3-3m)/(m^2-2m)<=2
(3-3m)/(m^2-2m)-2<=0
(3-3m-2m^2+4m)/(m^2-2m)<=0
(2m^2-m-3)/(m(m-2))>=0
(2m-3)(m+1)/m(m-2)>=0
所以,m<=-1,02