Lesson Objective: I will be able to … Find slope by using the slope formula Language Objective: I will be able to … Read, write, and listen about vocabulary, key concepts, and examples

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Example 1: Finding Slope by Using the Slope Formula Page 17 Find the slope of the line that contains (2, 5) and (8, 1). Use the slope formula. Substitute (2, 5) for (x1, y1) and (8, 1) for (x2, y2). The slope of the line that contains (2, 5) and (8, 1) is .

Find the slope of the line that contains (–2, –2) and (7, –2). Your Turn 1 Page 17 Find the slope of the line that contains (–2, –2) and (7, –2). Use the slope formula. Substitute (–2, –2) for (x1, y1) and (7, –2) for (x2, y2). = 0 The slope of the line that contains (–2, –2) and (7, –2) is 0.

Example 2: Finding Slope from Graphs Page 18 Example 2: Finding Slope from Graphs The graph shows a linear relationship. Find the slope. Let (0, 2) be (x1, y1) and (–2, –2) be (x2, y2). Use the slope formula. Substitute (0, 2) for (x1, y1) and (–2, –2) for (x2, y2). = 2

Example 3: Finding Slope from Tables Page 18 Example 3: Finding Slope from Tables The table shows a linear relationship. Find the slope. Step 1 Choose any two points from the table. Let (0, 1) be (x1, y1) and (–2, 5) be (x2, y2). Step 2 Use the slope formula. Use the slope formula. Substitute (0, 1) for and (–2, 5) for . The slope equals −2.

Example 4: Science Application Page 19 The graph shows the height of a plant over a period of days. Find the slope of the line. Then tell what the slope represents. Step 1 Use the slope formula. Step 2 Tell what the slope represents. In this situation y represents the height of the plant and x represents time. So slope represents in units of . A slope of means that the plant grows at a rate of 1 centimeter every two days.

Example 5: Finding Slope from an Equation Page 19 Example 5: Finding Slope from an Equation Find the slope of the line described by 4x – 2y = 16. Step 1 Find the x-intercept. Step 2 Find the y-intercept. 4x – 2y = 16 4x – 2y = 16 4x – 2(0) = 16 Let y = 0. 4(0) – 2y = 16 Let x = 0. 4x = 16 –2y = 16 - x = 4 or (4, 0) y = –8 or (0, -8) Step 3 The line contains (4, 0) and (0, –8). Use the slope formula.

Chapter 5 Quiz next class! Homework Assignment #23 Holt 5-3 #4-11, 26 Holt 5-4 #11-15, 18 After School Review on TUESDAY (Rm 46) Chapter 5 Quiz next class!