Focus Lesson

4-2 Tables and Graphs

Essential Question

How do you identify ordered pairs from a table of values?

Discovery School- Coordinate Planes X and Y Mark the Spot

Write down 3 facts from the video clip. 1. 2. 3.

Write the ordered pairs from the table.

(2, 1), (4, 7), (0, 9), and (5, 3).

Example 1

x y

2 1

4 7

0 9

5 3

(x, y)

(2, 1)

(4, 7)

(0, 9)

(5, 3)

Write the ordered pairs from the table.

(3, 4), (2, 8), (8, 3), and (1, 0).

Example 2

x y

3 4

2 8

8 3

1 0

(x, y)

(3, 4)

(2, 8)

(8, 3)

(1, 0)

Write and graph the ordered pairs from the table.

(1, 4), (1, 2), (3, 2), and (5, 0).

Example 3

x

y

–2

–2

2

2–4

–4

4

4

–1–3–5 531

1

3

5

0

–3

–5

–1

x y

1 4

1 2

3 2

5 0

• (1, 4)

(–1, –2) •

• (3, 2)(–5, 0)

•

Plot the points on a coordinate plane.

Write and graph the ordered pairs from the table.

(2, 3), (3, 3), (3, 2), and (2, 4).

Example 4

x

y

–2

–2

2

2–4

–4

4

4

–1–3–5 531

1

3

5

0

–3

–5

–1

x y

2 3

3 3

3 2

2 4

• (2, 3)

(–3, –3) • • (3, –2)

(–2, 4) •

Plot the points on a coordinate plane.

Steps for Word Problems

1. Pick out what the question is asking.

2. Write the ordered pairs3. Graph the ordered pairs4. Answer the questions

Graph the data given in the table showing the number of pounds of food purchased and its cost. 1. What appears to be the relationship between the number of pounds and the cost in the table below?

Example 5

Number of Pounds

1 2 3 4

Cost($) 1.85 3.70 5.55 7.40

2. Write the ordered pairs from the table.

(x, y) (1, 1.85) (2, 3.70) (3, 5.55) (4, 7.40)

(1, 1.85), (2, 3.70), (3, 5.55), and (4, 7.40).

0

2

4

6

8

10

0 2 4 6

Number of Pounds

The graph shows that the cost is the number of pounds multiplied by 1.85.

Cost

($)

Practice

(1, 1); (2, 1); (3,1); (4,1)

(8, 4); (10, 5); (12, 6); (14, 7)

(-2, 0); (-1, 9); (0, 18); (1, 27)

Practice

x

y

–2

–2

2

2–4

–4

4

4

–1–3–5 531

1

3

5

0

–3

–5

–1

x

y

–2

–2

2

2–4

–4

4

4

–1–3–5 531

1

3

5

0

–3

–5

–1

(1, -2) • (2, -1) •

(3, 0 ) • (4, 1 ) •

(-5, 4 ) •

(-3, 2 ) •

(-1, 0 ) •

(1 ,-2 ) •

Practice

(1, 1.50); (2, 3.00); (3, 4.50); (4, 6.00)

0

2

4

6

8

10

0 2 4 6

Number of Drinks

Cost

The graph shows that the number of drinks is multiplied by a $1.50.

Graded Practice

Homework

Workbook Page All problems

Closing

1. Write and graph the ordered pairs from the table.

x y

2 6

–10 10

–4 –4

–6 –8

x

y

–4

–4

4

4–8

–8

8

8

–2–6–10 1062

2

6

10

0

–6

–10

–2

• (2, 6)

(-10, 10) •

(-4, -4) •

(-6, -8) •

The ordered pairs are (2, 6), (-10, 10), (-4, -4), and (-6, -8).

Closing cont…

2. The table shows the number of hours a student studies for a test and scores. Graph the data to find the number of correct answers after studying for 6 hours. What appears to be the relationship between the number of hours of study and the score?

90; the score is multiplied by 15.

Hours 1 2 3 4

Scores 15 30 45 60