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Home > PC > Chapter 12 > Lesson 12.1.3 > Problem 12-30


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

The cost of pencils, pens, and erasers is . The cost of pencils, pens, and eraser is . The cost of pencil, pen, and erasers is . Find the cost of each item.

  1. Explain what she should do.

    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.

    Where , , .

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