1. Solve by substitution or elimination method:

3x - 2y = 8
-12x + 8y = 32

2. Solve by substitution or elimination method:

7x - 5y = 14
-4x + y = 27

3. Solve by substitution or elimination method:

-4x + 3y = 5
12x - 9y = -15

4. A university bookstore recently sold a wire bound graph-paper notebook for $2.50 and a college-ruled notebook for $2.30. At the start of spring semester, a combination of 50 of these notebooks was sold for a total of $118.60. How many of each type were sold?

5. Write a system of equations for each of the following, and solve each of the systems.

i. A unique solution.

ii. An infinite number of solutions.

iii. No solution.