Question

Let x represent the cost of a box of cereal and let y represent the cost of a half-gallon of milk. An augmented matrix involving x and y is shown below.
 

3  1  l7

1  1  l4
Which of the following situations can be modeled by this augmented matrix?

Answer 1

The augmented matrix represents the system
3x + y = 7
x + y = 4

So it models a situation where "three boxes of cereal and one half-gallon of milk cost $7, and one box of cereal and one half-gallon of milk cost $4."

Solving gives x = $1.50 (a box of cereal) and y = $2.50 (a half-gallon of milk).