1. y1=ax y2=b/x^2 y=ax+b/x^2;
19=2a+b/4
19=3a+b/9
联立得a=5 ,b=36
2.k/4-k/6=3 --> k=36, y=36/x
3.设甲单价x.乙y
3600/x+3600/y=750
4800/x+2400/y=700
联立得x=12 ,y=8
设利润为w 买进甲x件,则买进乙(7200-12x)/8
x
1. y1=ax y2=b/x^2 y=ax+b/x^2;
19=2a+b/4
19=3a+b/9
联立得a=5 ,b=36
2.k/4-k/6=3 --> k=36, y=36/x
3.设甲单价x.乙y
3600/x+3600/y=750
4800/x+2400/y=700
联立得x=12 ,y=8
设利润为w 买进甲x件,则买进乙(7200-12x)/8
x