1)解:设C县运到A县的化肥为吨,则D县到A县(90-x)吨,C县到B县(100-x)吨,虚盯D县到B县兄余(x-40)羡誉滚吨X>=090-x>=0(100-x)>=0(x-40)>=0所以40<=x<=902)解:W=35x+40(90-x)+30(100-x)+45(x-40) =10x+4800因为k=10>0所以W随X增大而增大x最小=40,此时W=5200 对吗????????????
吐血