1. What is the solution to the system of equations? 2x – 3y = -1
y – x = -1
(a) Use the substitution method to find the solution.
(b) What do you know about the two lines in this system of equations (Hint: Do they intersect? Are they parallel? Are they the same line?)

2. Use the linear combination method to solve the system of equations. What does the solution tell you about the two lines of the system?
2x + 8y = 6
-5x – 20y = -15

3. Mr. Perrins’s class sold packs of peanut butter cookies for $2.35 each and Mr. Woods’s class sold bottles of milk for $1.34 each. Together, the classes sold 73 items and earned $141.25 for their school.
(a) Write and solve a system of equations that model the problem. Show all your work.
(b) Which class earned more money?
(c) How much more money did that class earn?