{3x+y=1+3m}①{x+3y=1-m}②这条方程组的解满足X小于0Y大于0求M的取值范围②×3-①得8y=2-6my=1/4-3/4m③①×3-②得8x=2+6mx=1/4+5/4m④因滚戚为y>0,1/4-3/4m>0,m<1/3X<0,1/4+5/4m<0,m>-1/5所以大基陵答案锋芦为:-1/5(即-0.2