若方程組2X+3Y=2K-1,3X+2Y=K+1的解滿足X>Y>0,則K的取值范圍是
若方程組2X+3Y=2K-1,3X+2Y=K+1的解滿足X>Y>0,則K的取值范圍是
數(shù)學人氣:618 ℃時間:2019-08-20 04:18:40
優(yōu)質(zhì)解答
2X+3Y=2K-1,3X+2Y=K+1
相加5X+5Y=3K
X+Y=3K/5
2X+2Y=6K/5
2X+3Y=2K-1
所以Y=2K-1-6K/5=4K/5-1
X=3K/5-Y=1-K/5
X〉Y〉0
1-K/5>4K/5-1>0
4K/5-1>0
4K/5>1
K>5/4
1-K/5>4K/5-1
K<2
所以5/4