1. Warm-Up #29 (Friday, 11/13) Is (3,1) satisfy x + 2y = 6?
Find the slope of (0, 3) and (-5, -1)
Find the slope of (-2, 1) and (-2, 1)

2. Homework (Friday, 11/13)
Graphical Stories pg 3 and 4

3. Lesson 3.12 Rates of Change

4. OBJECTIVE:
Finding rates of change from tables and graphs.

5. Suppose you type 140 words in 4 minutes. What is your typing rate?
RATES OF CHANGE
Suppose you type 140 words in 4 minutes. What is your typing rate?
140 words
4 min
35 words
1 min =
The number of words depends on the number of minutes you type. So, the number of words is the dependent variable.

6. “Rate of change”: change in Y (dependent)
RATES OF CHANGE
You use a rate of change to find the amount of one quantity per one unit of another, such as typing 35 words in 1 min.
The RATE OF CHANGE allows you to see the relationship between two quantities that are changing.
“Rate of change”: change in Y (dependent)
(slope) change in X (independent)

7. RATES OF CHANGE $19.95 $3.99 5 yd 1 yd = 268.8 mi 22.4 mi 12 gal 1 gal
Write each as a rate.
You buy 5 yards of fabric for $19.95.
You travel mi on 12 gal of gasoline.
$19.95
5 yd
$3.99
1 yd =
268.8 mi
12 gal
22.4 mi
1 gal =

8. Example 1:
A climber is on a hike. After 2 hours he is at an altitude of 400 feet. After 6 hours, he is at an altitude of 700 feet. What is the average rate of change?

9. Example 2:
After 30 baseball games, A-Rod had 25 hits. If after 100 games he had 80 hits, what is his average hits per baseball game.

10. Example 3:
A snack bar is having a sale on hamburgers. At 9:00AM, the snack bar has sold 28 hamburgers. At 12:00PM, the snack bar discovers that it has sold 103 hamburgers. What is the average rate of change between 9:00AM and 12:00PM?