Title: Lesson 5-7
Author: mark_cameron
Last saved by: gtsmith
Company: McGraw-Hill

Lesson 4-9

Example 1 Naming Points Using Ordered Pairs

O      2     4      6     8     x

     Y

8

6

4

2

B

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Write the ordered pair that names point B.

Step 1 Start at the origin. Move right along the x-axis until you are under point B. The x-coordinate of the ordered pair is 5.

Step 2 Now move up until you reach point B. The y-coordinate is 6.

So, point B is named by the ordered pair (5, 6).

O      2     4      6     8     x

     Y

8

6

4

2

●

A

Example 2 Graphing Ordered Pairs
Graph the point A(2, 5).
•	Start at the origin.
•	Move 2 units to the right on the x-axis.
•	Then move 5 units up to locate the point.
•	Draw a dot and label the dot A.

Example 3 Graphing Ordered Pairs

O      2     4      6     8     x

     Y

8

6

4

2

●

D

Graph the point D(4, 31/2).
•	Start at the origin.
•	Move 4 units to the right on the x-axis.
•	The value 31/2 is halfway between 3 and 4. So, on the y-axis move up halfway between 3 and 4.
•	Draw a dot and label the dot D.

O              1            2      x

     Y

2

1

●

R

Example 4 Graphing Ordered Pairs
Graph the point R(1.75, 2).
•	Start at the origin.
•	The value 1.75 is three-fourths of the way between 1 and 2. So, on the x-axis move three-fourths of the way between 1 and 2.
•	Then move 2 units up to locate the point.
•	Draw a dot and label the dot R.

Example 5 Real-World Example
Raffle Tickets
Number of Tickets | Cost ($)
1 | 1.5
2 | 3
3 | 4.5
4 | 6
RAFFLE   Mr. King’s class is conducting a raffle to raise money for a local charity organization. The costs of 1, 2, 3, and 4 raffle tickets are shown in the table. List this information as ordered pairs (number of tickets, cost).
 
The ordered pairs are (1, 1.5), (2, 3), (3, 4.5), and (4, 6).

Example 6 Real-World Example
Graph the ordered pairs in Example 5. Then describe the graph.

O      2     4      6     8     x

     Y

8

6

4

2

●

●

●

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The points appear to fall on a line.