1. slope = change in y change in x Understanding Slope COURSE 3 LESSON 3-3 Using coordinates, find the slope of the line between P (–2, 3) and Q (–1, –1). 3 – (–1) –2 – (–1) = Subtract the coordinates of point Q from the coordinates of point P. 4 –1 = or –4 Simplify. 3-3

2. Understanding Slope COURSE 3 LESSON 3-3 Find the slope of the line in the graph. Describe how one variable changes in relation to the other. 75 – 25 300 – 100 = Use coordinates of two points. = 50 200 Subtract. The cost increases by $25 for every 100 miles traveled. slope = change in y change in x Simplify. 1414 = 3-3

3. Understanding Slope COURSE 3 LESSON 3-3 Find the slope of each line. State whether the slope is zero or undefined. a. line k Division by zero is undefined. The slope of a vertical line is undefined. b. line p The slope of a horizontal line is zero. slope = = = 0 2 – 2 –2 – 3 0 –5 slope = = 1 – (–3) 2 – 2 4040 3-3

4. Understanding Slope COURSE 3 LESSON 3-3 The data in the table below are linear. Use the data to find the slope. Then graph the data and the line. x–10 1 2 y–11 3 5 + 1 + 1 + 1 + 2 + 2 + 2 slope = = or 2 change in y change in x 2121 3-3

5. Understanding Slope 1.Find the slope of each line. a. line sb. line t 2.The data in the table below is linear. Find the slope. x 2 4 5 9 y–6–12–15 –27 COURSE 3 LESSON 3-3 undefined –3 2323 3-3