(1)设从甲仓库调往A县农用车x辆,则调往B县农用车=12-x,乙仓库调往A县的农用车=10-x;
(2)到A的总费用=40x+30(10-x)=10x+300;
到B的总费用=50(12-x)+80(x-4)=30x+280.
(3)当x=4时,到A的总费用=10x+300=340,
到B的总费用=30x+280=400.
故总费用=340+400=740.
(1)设从甲仓库调往A县农用车x辆,则调往B县农用车=12-x,乙仓库调往A县的农用车=10-x;
(2)到A的总费用=40x+30(10-x)=10x+300;
到B的总费用=50(12-x)+80(x-4)=30x+280.
(3)当x=4时,到A的总费用=10x+300=340,
到B的总费用=30x+280=400.
故总费用=340+400=740.