x-y=mx=m+y带入2x+y=m+3得2m+3y=m+33y=3-my=1-(1/3)m将之带入x=m+y得x=m+1-(1/3)mx=(2/3)m+1由题,x-y=m 2x+y=m+3的解是正数所以,1-(1/3)m＞0-（1/3）m＞-1(1/3)m＜1m＜3(2/3)m+1＞0(2/3)m＞-1m＞-1.5且由题,m＜0,所...