CPM Homework Help : PC Problem 12-30

Juanita wants to solve the following problem using matrices, but is not sure how. Homework Help ✎
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.
2. Solve this problem.

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?

Step (b):

Where x = cost of 1 pencil, y = cost of 1 pen, z = cost of 1 eraser.

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