Set up a system of linear equation for each question. Write each system as an augmented matrix. You do not have to solve the systems.

Company X plans to spend $500,000 on 20 new computers. Each model A computer will cost $2,000, each model B $2,500, and each model C $3,500. Company X has decided that they need twice as many model A computers as Model B computers. How many of each kind of computers can the company buy?

A baseball park has 7000 seats. Box seats cost $6, grandstand seats cost $4, and bleacher seats cost $2. When all seats are sold, the revenue is $26,400. If the number of box seats is one-third the number of bleacher seats, how many seats of each type are there?

The population of a state was approximately 24 million in 1980, 30 million in 1990, and 34 million in 2000. Construct a model for this data by finding a quadratic equation whose graph passes through the points (0,24), (10,30), and (20,34).

Hint: You need to setup a system of linear equations with the intent of finding a quadratic equation that models the information given above. You only need to setup the system; you do not need to find the quadratic equation that models the information. You should have three equations. Use the general form of the quadratic equation, y= ax2 + bx + c, to help you setup each equation.