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L1:(3+M)X+4Y=5-3M
L2:2X+(5+M)Y=8
L1:(3+M)X+4Y=5-3M ==>y=〔5-3M -(3+M)X〕/4
L2:2X+(5+M)Y=8 ==>y=(8-2x)/(5+m)
1.相交
〔5-3M -(3+M)X〕/4=(8-2x)/(5+m)
m≠-1,-7
2.平行
k1=k2,-(3+M)/4=-2/(5+m) m=-1,-7
3.垂直
k1*k2=-1,(3+M)/4 * 2/(5+m)=-1,m=-13/3
1年前
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