A large commercial farm needs 35,000 pounds of potash, 68,000 pounds of nitrogen, and 25,000 pounds of phosphoric acid. Three brands of fertilizer, GrowRite, MiracleMix, and GreatGreen, are available and contain the amounts of potash, nitrogen and phosphoric acide per truckload listed in below. How many truckloads of each brand should be used to provide the required potash, nitrogen and phosphoric acid? Please Show work.
Pounds Per Truck Load: Grow Rite MiracleMix GreatGreen
Postash 400 600 700
Nitrogen 500 1000 1600
Phosphoric Acid 300 400 500