1. Graphing Linear Equations

2. An equation for which the graph is a line
Linear Equation
An equation for which the graph is a line

3. Any ordered pair of numbers that makes a linear equation true.
Solution
Any ordered pair of numbers that makes a linear equation true.
(9,0) IS ONE SOLUTION
FOR Y = X - 9

4. Linear Equation
Example:
y = x + 3

5. Graphing
Step 1:
~ Three Point Method ~
Choose 3 values for x

6. Find solutions using table
Graphing
Step 2:
Find solutions using table
y = x + 3
Y | X 1 2

7. Graph the points from the table
Graphing
Step 3:
Graph the points from the table
(0,3) (1,4) (2,5)

8. Draw a line to connect them
Graphing
Step 4:
Draw a line to connect them

9. Graph using a table (3 point method)
Try These
Graph using a table (3 point method)
1) y = x + 3
2) y = x - 4

10. Where the line crosses the x-axis
X-intercept
Where the line crosses the x-axis

11. The x-intercept has a y coordinate of ZERO

12. To find the x-intercept, plug in ZERO for y and solve

13. Describes the steepness of a line
Slope
Describes the steepness of a line

14. Slope
Equal to:
Rise
Run

15. The change vertically, the change in y
Rise
The change vertically, the change in y

16. The change horizontally or the change in x
Run
The change horizontally or the change in x

17. Finding Slope Step 1: Find 2 points on a line (2, 3) (5, 4)
(2, 3) (5, 4)
(x1, y1) (x2, y2)

18. Find the RISE between these 2 points
Finding Slope
Step 2:
Find the RISE between these 2 points
Y2 - Y1 =
4 - 3 = 1

19. Find the RUN between these 2 points
Finding Slope
Step 3:
Find the RUN between these 2 points
X2 - X1 =
5 - 2 = 3

20. Write the RISE over RUN as a ratio
Finding Slope
Step 4:
Write the RISE over RUN as a ratio
Y2 - Y1 = 1
X2 - X

21. Where the line crosses the y-axis
Y-intercept
Where the line crosses the y-axis

22. The y-intercept has an x-coordinate of ZERO

23. To find the y-intercept, plug in ZERO for x and solve

24. Slope-Intercept
y = mx + b
m = slope
b = y-intercept

25. Mark a point on the y-intercept
Step 1:
Mark a point on the y-intercept

26. Define slope as a fraction...
Step 2:
Define slope as a fraction...

27. Step 3: Numerator is the vertical change
(RISE)

28. Denominator is the horizontal change
Step 4:
Denominator is the horizontal change
(RUN)

29. Graph at least 3 points and connect the dots
Step 5:
Graph at least 3 points and connect the dots