1. Quick Start Expectations 1.Fill in planner and HWRS HW: p. 46, #5, 14, 16, 18, #39-42 2.Get a signature on HWRS 3.On desk: calculator, journal, HWRS, pencil, pen 4.Warm Up: next slide… back of HWRS

2. What tool can we use to solve for the slope? The slope algorithm! (x 1,y 1 ) (x 2, y 2 ) y 2 – y 1 x 2 – x 1 (x 1,y 1 ) (x 2, y 2 ) 9 – 5 6 – 4 = 4/2 = 2 m = What tool can we use to solve for the y-intercept? A table! XY 4 5 3 2 1 1 -1 0 -3 What is the equation? y = 2x + -3 Write an equation for the line with points (4, 5) and (6, 9)

7. As the number in the group increases by 1, the admission cost increases by $15. Slope = 15 y-intercept = 60

8. y = 2.5x

9. Decide what the independent and dependent variables are. Find the unit rate (m, or slope). Look if the starting value (b) was given. If not work backwards to find when x = 0.

10. Find the slope (m) Finding out the y-value change as x increases by 1. Use the slope algorithm Change in y divided by the change in x Find the y-intercept (b) Work backwards from the given points to point (0, b) using slope Use substitution with the slope and a given point (x, y)

11. Find the slope (m) Find 2 points the line passes through Use the slope algorithm Find the y-intercept (b) Work backwards from the given points to point (0, b) using slope Use substitution with the slope and a given point (x, y)

12. Dana’s work is correct. In general, if you know the slope of a line and a point on the line you can substitute these three values in for y, m, and x in the equation y = mx + b and solve the equation for b.

13. No, Chris has not used the coordinates of the two points correctly to find the slope. She put the differences in x on top! It should be the change in y divided by the change in x, for a slope of 2. The equation should be y = 2x – 3.