MAT 117 QUIZ 7-2

1. Use your calculator to solve the following system of linear equations.  Answer as ordered pairs.

                                                   4x + 7y = -5

                                                  -5x + 6y = -38

2. At Karol’s Kandy Store, peanuts cost $3.50 per pound and cashews cost $5.00 per pound.  John bought a 20 pound mixture of peanuts and cashews and it cost him $80.50.  How many pounds of each were in the mixture?

3. Toezies’ is a company that makes slippers.  They pay fixed fees of $4300 every month.  It costs them $1.55 in labor and materials to produce each pair of slippers.  The slippers sell for $5.00 per pair. 

a) Find the monthly cost function.

b)Find the monthly revenue function.

c) At minimum, how many pairs of slippers must the company produce and sell in order to make a profit?

4. How many gallons of a 15% juice solution must Audrey mix with 4 gallons of a 50% juice solution to make a 20% juice solution?  Round to two decimal places.

5. Jack had a total of $34000 invested into two accounts.  One paid 3.5% simple interest, and the other paid 4%.  If he made a total of $1279 in interest after one year, then how much was invested in each account?

6. Joelle has access to two solutions, one is 0.25% acid and the other is 0.40 % acid.  How much of each should she mix to make 60 liters of a 0.35% acid solution?