EXAMPLE 1
6.
on p. 427
for Exs. 6–11
★ MULTIPLE CHOICE Which ordered pair is a solution of the linear system
x 1 y 5 22 and 7x 2 4y 5 8?
A (22, 0)
7.
B (0, 22)
C (2, 0)
D (0, 2)
★ MULTIPLE CHOICE Which ordered pair is a solution of the linear
system 2x 1 3y 5 12 and 10x 1 3y 5 212?
A (23, 3)
B (23, 6)
C (3, 3)
D (3, 6)
SOLVING SYSTEMS GRAPHICALLY Use the graph to solve the linear system.
Check your solution.
8. x 2 y 5 4
9. 2x 1 y 5 22
2x 2 y 5 6
4x 1 y 5 1
10. x 1 y 5 5
22x 1 y 5 24
y
y
y
1
1
x
1
1
1
11. ERROR ANALYSIS Describe
and correct the error in solving
y
the linear system below.
x 2 3y 5 6
2x 2 3y 5 3
1
x
Equation 1
Equation 2
x – 3y = 6 x
1
–1
x
The solution is
(3, 21).
2x – 3y = 3
EXAMPLE 2
GRAPH-AND-CHECK METHOD Solve the linear system by graphing. Check
on p. 428
for Exs. 12–26
your solution.
12. y 5 2x 1 3
y5x11
13. y 5 2x 1 4
y 5 2x 2 8
14. y 5 2x 1 2
15. x 2 y 5 2
x 1 y 5 28
16. x 1 2y 5 1
22x 1 y 5 24
17. 3x 1 y 5 15
18. 2x 2 3y 5 21
5x 1 2y 5 26
19. 6x 1 y 5 37
4x 1 2y 5 18
20. 7x 1 5y 5 23
21. 6x 1 12y 5 26
2x 1 5y 5 0
22. 2x 1 y 5 9
2x 1 3y 5 15
23. 25x 1 3y 5 3
13
1
3
24. }
x1}
y5}
8
2
1
25. }
x2}
y 5 2}
26. 21.6x 2 3.2y 5 224
4
2
3
13
x 2 }y 5 }
4
2
4
5
5
y 5 4x 1 6
5
3
2}
x1y53
y 5 215
29x 1 y 5 211
4x 1 3y 5 30
2.6x 1 2.6y 5 26
4
3
Find values for m and b so that the system y 5 }
x21
5
and y 5 mx 1 b has (5, 2) as a solution.
27.
★ OPEN – ENDED
28.
★ WRITING Solve the linear system shown
by graphing. Explain why it is important to
check your solution.
y 5 4x 2 1.5
y 5 22x 1 1.5
Equation 1
Equation 2
7.1 Solve Linear Systems by Graphing
431