## Matrix Algebra - Add and Multiply - from 6.1

Which of the following expressions is defined?

A+B, AC, CA, DC

For those expressions that are defined, find the product.

## Matrix Algebra - Divide Over - from 6.2

## Matrix Algebra - Multiply and Inverse - from 6.2

## Matrix Algebra - Divide Over II - from 6.2

BA = D. What is B?

## Advanced Inverse Problem - from 6.2

For what value of c would make A non-invertible?

## Matrix Algebra - Inverse - from 6.2

## Linear Economic Model - Copper and Electricity - from 6.3

It takes .4 units of copper and .7 units of electricity to produce a unit of copper. It takes .2 units of copper and .6 units of electricity to produce a unit of electricity. The demand for copper and electricity are 20 and 80, respectively. How many of units of each needed to be produce in order to satisfy demand?