2x+y=1+3mx+2y=1-m解得x=(1+7m)/3y=(1-5m)/3x+y<0(1+7m)/3+(1-5m)/3<0解得m<-1
m<-1
两个方程相加得3(x+y)=2(m+1)解满足x+y<0,所以m+1<0所以m<-1
