### Home > PC3 > Chapter 9 > Lesson 9.1.4 > Problem 9-86

9-86.

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

The cost of two pencils, two pens, and two erasers is

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?

Solve this problem.

Solve for

andusing a calculator.