设x+3y=0,2x-y-3=0→x=9/7,y=-3/7→9=x+y=9/7+-3/7=6/7(舍去)设x+3y=0,x-my+1=0→x=-3/(m+3),y=1/(m+3)→9=x+y=-3/(m+3)+1/(m+3)=-2/(m+3)→m=-29/9设2x-y-3=0,x-my+1=0→x=(3m+1)/(2m-1),y=5/(2m-1)→9=x+y=(3m+1)/(2m-1)+5/(2m-1)=3(m+2)/(2m-1)→m=1
-29/9
回家考试结果怎么样?