1. SILENTLY Algebra 1 10/11 Jan 2011 SILENTLY Write down HOMEWORK DUE next class pg. 222: 10, 11a Write the given information and explain your answers. WARM UP  y = 3x + 2 solve for y when: 1. x = -2 2. x = -1 3. x = 0 4. x = 1 5. x = 2

2. Objective Students will be able to find equations from graphs, tables and scatter plots. Yesterday’s - Class work student exemplars discuss work

3. Supply Check and Syllabus Supplies to bring to every class: composition book lined paper and graph paper pencil text book KEEP loose papers in a binder.

4. Hector recently signed up for a limited use internet provider. He pays a flat monthly charge and an hourly rate for the number of hours he is connected: Slope MonthTime (hr)Total fee ($) September4016.55 October5019.45 November8028.15 1. DISCUSSION: Is there a linear relationship between time and fee? What is the hourly rate in dollars per hour? How do you know? 2. Plot and label the three points on graph paper.

5. 3. Use 2 points on your graph and make a slope triangle. Use arrows to show how you can move from one point to the other using ONLY ONE VERTICAL arrow and ONE HORIZONTAL arrow. How long is each arrow? What are the units? How do the arrows relate to the hourly rate you found earlier? 4. Make a slope triangle using TWO DIFFERENT POINTS and repeat step 3. What do you notice? see http://www.keymath.com/x7022.xml

6. xy 12 46 (4, 6) (1, 2) 6 - 24 - 1

7. (x 1, y 1 ) (x 2, y 2 ) xy x1x1 y1y1 x2x2 y2y2 y 2 -y 1 (x 2 -x 1 )

8. Practice Find the slope of the line containing the 2 points that are given: 1. (2, 4) and (6, 8) 2. (8, 9) and (20, 25) 3. (5, 6) and (-10, -20) Do worksheets Lesson 4.1: 1, 2, 4 Lesson 4.2: 1-3 GROUPS-- be ready to share 4.1 #3