Math 106 Extra Credit 8 Oct 2013 Name________________________________________

Show ALL work. Work on your own. You may use your book or notes.

1. Use Cramer's Rule to solve the system:

3x + 2 z = 1

2y – z = 1

x + 2y = 1

2. Graph the system of inequalities. Shade and label the solution set. Check a point IN the solution set to show it satisfies the inequalities.

3. A chemistry experiment requires a 10% hydrogen peroxide solution. How much of a 3% hydrogen peroxide solution must be added to 16 ounces of a 30% hydrogen peroxide solution to yield a 10% solution?

4. A piggy bank is full of dimes and quarters. The total value of the coins is $14.05. If there are a total of 100 coins, how many of each does she have?