2x+3y=11-m (1)
3x+2y=2m+1 (2)
(1)*2-(2)*3 -5x=19-8m x=(8m-19)/5
(1)*3-(2)*2 5y=31-7m y=(31-7m)/5
因x,y都是正值
则(8m-19)/5>0
(31-7m)/5>0
解得19/8