2. Slope Intercept Form & Graphing

3. Definition - Intercepts x-intercept y-intercept BACK The x-intercept of a straight line is the x-coordinate of the point where the graph crosses the x-axis. The y-intercept of a straight line is the y-coordinate of the point where the graph crosses the y-axis. x y

4. -4 1-3-223 -2 5 4 3 2 1 0 -5 -3 What is the y-intercept? b = 3 b = -4 b = -3 b = 5 b = 0

5. y = mx + b Slope-Intercept Form BACK y = 5x + 2

6. Slope is Rise over Run. The numerator tells you to go up or down Positive = Up, Negative = Down. The denominator tells you how far to run left or right. Positive = Right, Negative = Left. BACK

7. Up 1, Right 3. Up 2, Left 1. Down 2 Right 3 or Up 2, Left 3 BACK

8. Finding the slope and y-intercept State the slope and y-intercept of: y = 3x + 2 BACK

9. Up/Down Left/Right The slope is 3 or 3/1 which means up 3 and right 1. BACK

10. y = 3x + 2 Slope = 3/1 y-intercept= 2 Up 3 and Right 1 BACK

11. When am I ever going to use this?

12. y = -2x + 3 Slope = -2/1 y-intercept= 3 Down 2 and Right 1 BACK

13. y = 3x -2 You try this one BACK

14. y = 3x -2 BACK

15. 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 BACK

16. Changing equations to the form y = mx + b BACK

17. 2x + 4y = 8 changed to y = -1/2x + 2 y-intercept= 2 Slope = -1/2 Down 1 Right 2 BACK

18. Now you change 2x + 3y = 6 to y = mx + b BACK

19. 2x + 3y = 6 changed to y = -2/3x + 2 BACK

20. Parallel Lines Same or different The equations of two parallel lines have the same slope, but two different y-intercepts.

21. y = 3x + 4 and y = 3x - 2 y = 3x + 4 y = 3x -2 BACK

22. What if there is no constant? If you have a problem like: y = 3x You can add a zero, “+ 0”, to the equation without changing the value. BACK

23. Hints If y = x + 3,the coefficient of x is 1, so the slope is 1/1. If you do not have room to graph a slope of 2/1 you can use the equivalent fraction -2/-1 BACK

24. Slope Intercept Form & Graphing BACK