Example Problems Answers
1. Solve the system by graphing: x +
y = 5 y = -x + 5
2x - y = 4 y = 2x - 4
2. Solve the system using
substitution: 5x + 3y = -4
7x - y = 36
y = 7x - 36
then 5x + 3(7x-36) = -4
5x + 21x - 108 = -4
26x = 104
x = 4
y = 7(4) - 36
y = -8
intersection is (4,-8)
3. Solve the system using
elimination: 2x - y = 4
2x + 3y = 12
6x - 3y = 12
2x + 3y = 12
8x = 24
x = 3
2(3) - y = 4
-y = -2
y = 2
intersection is
(3,2)
4. Solve the system using either
method: x + y = 6
3x - 4y = 4
| 4x + 4y = 24 3x - 4y = 4 7x = 28 x = 4 4 + y = 6 intersection is (4,2) |
y
= 6 - x 3x - 4(6 - x) = 4 4 + y = 6 intersection is (4,2) |
5. Graph the inequality:
y ³ -x +
5
y³ 1½x -
5
