1. Bellwork: Use the slope formula to find the slope.
y2 - y1 x2 - x1
m =
1.) (6,8) & (0,-5)
2.) (4,-3) & (4, 9)
3.) (8,3) & (-1,3)
4.) (2,3) & (8, -3)

2. Bellwork: Use the slope formula to find the slope.
1.) (6,8) & (0,-5)
m = 13/6
2.) (4,-3) & (4, 9)
m = 12/0 = undefined

3. Bellwork: Use the slope formula to find the slope.
3.) (8,3) & (-1,3)
m = 0/-9 = 0
4.) (2,3) & (8, -3)
m = -6/6 = -1

4. Do the 6 graphs worksheet for review.
Classwork #1
Do the 6 graphs worksheet for review.

5. Classwork #2
Do worksheet 5.1 (13-18)

6. Write an equation of the line using the point-slope form.
Today’s Objective
Write an equation of the line using the point-slope form.

7. Equations of Lines Vertical line x = # Horizontal line y = #
Slope, y-intercept y=mx+b
Point, Slope y-y1=m(x-x1)
Standard Form Ax+By = C

8. Converting the slope formula to the point-slope form
Multiply both sides by (x2 - x1)
m(x2 - x1) = (y2 - y1)
(y2 - y1) = m(x2 - x1)
y2 - y1 x2 - x1
m =

9. Consider
A line containing the point (x1,y1) = (2,5) with a slope of 2/3.
Let (x,y) be any other point on the line. (see the graph)

10. Point =(2,5) ,Slope = 2/3 Y
(x,y)
(x1,y1) X

11. Write an equation of the line
Using the point-slope form if the point (x1,y1) = (2,5) and the slope is .
y - y1 = m(x - x1)
Point-Slope Form
Substitute point & slope in for (x1,y1)
y - 5 = (x - 2)

12. y = x + 3 2/3 y-5= x - 4/3 y - y1 = m(x - x1) y - 5 = (x - 2)
Point-Slope Form
Substitute Point & slope in for (x1,y1)
Distribute  to (x -2)
y-5= x - 4/3
y = x-4/3+ 5
Add 5 to both sides.
y = x + 3 2/3
The equation of the line.

13. Point =(2,5) ,Slope = 2/3 Y X
y = x + 3 2/3

14. Write an equation of the line
Using the point-slope form if the point (x1,y1) = (2,3) and the slope is -½.
y - y1 = m(x - x1)
Point-Slope Form
Substitute point & slope in for (x1,y1)
y - 3 = -½(x - 2)

15. y =-½x + 4 y - 3 =-½x + 1 y - y1 = m(x - x1) y - 3 = -½(x - 2)
Point-Slope Form
Substitute Point & slope in for (x1,y1)
Distribute -½ to (x -2)
y - 3 =-½x + 1
y =-½x
Add 3 to both sides.
y =-½x + 4
The equation of the line.

16. Point =(2,3) ,Slope =-½ Y X
y =-½x + 4

17. Write an equation of the line
Now pick a point
Using the point-slope form if the point (x1,y1) = (-3,6) and the point (x2,y2)=(1,-2)
y2 - y1 x2 - x1
-8 4
m = -2

18. y =-2x + 0 y - 6 =-2x - 6 y - y1 = m(x - x1) y - 6 = -2(x - -3)
Point-Slope Form
Substitute Point & slope in for (x1,y1)
Distribute -2 to (x +3)
y - 6 =-2x - 6
y =-2x
Add 6 to both sides.
y =-2x + 0
The equation of the line.

19. Write an equation of the line
You try these
1.) (x1,y1) = (-1,2) slope = -1
2.) (x1,y1) = (1,3) slope = 1/3

20. Write an equation of the line
1.) (x1,y1) = (-1,2) slope = -1
y - y1 = m(x - x1)
y - 2 = -1(x - -1)
y - 2 = -x -1
y = -x +1

21. Write an equation of the line
2.) (x1,y1) = (1,3) slope = 1/2
y - y1 = m(x - x1)
y - 3 = 1/2(x - 1)
y - 3 = 1/2x - 1/2
y = 1/2x+5/2

22. Write an equation of the line
You try these
Write an equation of the line
3.) (x1,y1) = (0,2) (x2,y2) = (3,-2)
4.) (x1,y1) = (5,0) (x2,y2) = (0,-3)

23. Write an equation of the line
3.) (x1,y1) = (0,2) (x2,y2) = (3,-2)
m= (-2-2)/(3-0) = -4/3
y = -4/3(x - 3)
y + 2 = -4/3x + 4
y = -4/3x + 2

24. Write an equation of the line
4.) (x1,y1) = (5,0) (x2,y2) = (0,-3)
m= (-3-0)/(0-5) = 3/5
y - 0 = 3/5(x - 5)
y - 0 = 3/5x - 3
y = 3/5x - 3

25. Classwork
Do worksheet 5.6
homework page 274 (1-5 & 9-18)