1. 5-1 Slope Objectives: 8.EE.5 I can find the rate of change given two ordered pairs S. Calahan 2008

2. Slope Slope is easy, Slope is fun, Just remember rise over run.

3. How do you find slope? Since slope is the ratio of the change in the y- coordinate to the change in the x-coordinate as you move from one point to the other.

4. Slope Slope = rise run = the change in y-coordinates the change in x-coordinates

5. Find the slope A line passes through points (-3, 2) and (5, 5). Use the formula ( m = slope) m = y 1 – y 2 change in y x 1 – x 2 change in x

6. (-3, 2) and (5, 5) m = 5 – 2 5 – (-3) = 3 8 So the slope is 3/8.

7. (-2, -8) and (-3, -4) m = -4 – (-8) remember to add the -3 – (-2) opposite = 4 = -4

8. (-3, 4) and (4, 4) m = 4 – 4 4 – (-3) = 0 = 0 7 The slope is 0.

9. (-2, -4) and (-2, 3) m = 3 – (-4) -2 – (-2) = 7 0 Since division by zero is undefined, the slope is undefined.

10. Classifying Lines positive negative slope of 0 undefined slope

11. Find the value of r So that the line through (6, 3) and (r, 2) has a slope of ½. m = y 1 – y 2 x 1 – x 2

12. Substitute into the formula 2 – 3 = 1 simplify 2 – 3 = -1 r – 6 2 -1(2) = 1(r – 6) use cross products -2 = r – 6 use distributive prop. +6 4 = r