2.) A phone company has two different phone plans.

- Plan A: $45 a month for unlimited

- Plan B: $15 a month plus $0.10 a minute

a)What will be the cost equation for Plan A and Plan B?

b)Create an inequality that models the conditions. Solve the inequality to find out how many calls must be made to make Plan A the better deal.

3.) A company that manufactures aquariums has a fixed cost of $116,000. It costs $150 to produce each aquarium. The selling price is $350 per aquarium. How many aquariums does the business need to sell to break even?

4.) Solve the following system of equations using elimination or matrices.

X - 2y + z = 6

2x + y - 3z = -3

X - 3y + 3z = 10