8. Solve the system by graphing.
3x + y = –1
9x + 3y = –3
9. Solve the system by graphing.
x + y = 4
–x + y = 2
11. Solve the following system of linear inequalities by graphing.
x – y <= 3
x + 2y >= 6
12. Solve the following system of linear inequalities by graphing.
3x – y < 2
x + y > 2
13. Solve the system by graphing.
3x + y = 6
3x – y = 0
14. Solve the system by graphing.
2x + y = 4
x + y = 3
15. A home-based company produces both hand-knitted scarves and sweaters. The scarves take 2 hours of labor to produce, and the sweaters take 14 hours. The labor available is limited to 40 hours per week, and the total production capacity is 5 items per week. Write a system of inequalities representing this situation, where x is the number of scarves and y is the number of sweaters. Then graph the system of inequalities.
18. Solve the following system of linear inequalities by graphing.
x – 3y > 6
3x + 2y > 12
20. Solve the system by graphing.
x + y = 3
x + y = –1