Suppose you want to fill nine 1-lb tins with a snack mix. You plan to buy almonds for 2.45/lb , peanuts for 1.85/lb , and raisins for .80 /lb . You want the mix to contain twice as much nuts as raisins by weight. If you spend exactly 15 , how much of each ingredient should you bu

b. How can you represent this system using a matrix equation?