1. Bellwork
1.) Make a “T” table and graph the equation 2x + 4y = 8
2.) Find the x and y intercepts and check your graph in #1 to see if they are correct.

2. 2x + 4y = 8 Y
y-intercept = 2 X
x-intercept = 4

3. Today’s Objective
To be able to change an equation to y = mx + b (Slope-intercept) form and create a quick graph of the equation.

4. Where m is the Slope & b is the y-intercept
Equation Forms
Standard Form
ax + by = c
Slope-Intercept Form
y = mx + b
Where m is the Slope & b is the y-intercept

5. Finding the slope and y-intercept
Find the Slope and y-intercept of the following equation.
y = 3x + 2

6. Finding the slope and y-intercept
When the equation is in the form y = mx + b The slope is m, and the y-intercept is b, So…...

7. y = mx + b For the equation y = 3x + 2 The Slope is 3
The y-intercept is 2

8. Graphing equations in the form y = mx + b
Graph the equation y = 3x+ 2
The y-intercept is 2
The slope is 3 which means the rise is 3 and the run is 1.
So….

9. y = 3x + 2 Y
Slope = 3
y-intercept= 2 X
Up 3 and over 1

10. y = -2x + 3 Y
Slope = -2
y-intercept= 3 X
Down 2 and over 1

11. y = 3x -2
You try this one Y X

12. y = 3x -2 Y
Slope = 3
y-intercept= -2 X
Up 3 and over 1

13. Changing equations to the form y = mx + b
When equations are in the form ax + by = c, then you need to change them to y = mx + b

14. Changing equations to the form y = mx + b
2x + 4y = 8
2x - 2x + 4y = 8 - 2x
4y = -2x + 8
4y/4 = (-2x + 8)/4
y = -2/4x + 2 or
y = -1/2x + 2

15. 2x + 4y = 8 changed to y = -1/2 + 2 Down 1 right 2
Slope = -1/2 rise = -1 run = 2
y-intercept= 2 X
Down 1 right 2

16. Now you change 2x + 3y = 6 to y = mx + b
2x - 2x + 3y = 6 - 2x
3y = -2x + 6
4y/3 = (-2x + 6)/3
y = -2/3x + 2

17. 2x + 3y = 6 changed to y = -2/3 + 2 Down 2 right 3
Slope = -2/3 rise = -2 run = 3
y-intercept= 2 X
Down 2 right 3

18. Slopes of Parallel Lines
Slopes of Parallel Lines must be the same…. So…..
y= 3x and
y = 3x are Parallel Lines
Notice: The equations have the same slope.

19. y = 3x + 4 and y = 3x - 2 Y
y = 3x + 4 X
y = 3x -2

20. Classwork
Do worksheet 4.5
homework
page 208 (2-32 even)