Juanita wants to solve the following problem using matrices, but is not sure how.

The cost of $2$ pencils, $2$ pens, and $2$ erasers is $$2.46$. The cost of $2$ pencils, $5$ pens, and $1$ eraser is $$4.38$. The cost of $1$ pencil, $1$ pen, and $2$ erasers is $$1.38$. Find the cost of each item.

1. Explain what she should do.

   Hint (a):

   Think about how you would write an equation for each sentence.
   What would your system of equations look like?
   How could you write your system as a matrix equation instead?

2. Solve this problem.

   Step (b):

   Where $x = \text{cost of } 1 \text{ pencil}$, $y = \text{cost of } 1 \text{ pen}$, $z = \text{cost of } 1 \text{ eraser}$.

   Solve for $x$, $y$, and $z$ using your calculator.See problem 12-19 if you need more help.