1. Do Now
In words, describe how to plot (5, –2) in words onto a coordinate plane.
Graph y = –x – 2 with the domain of -2, -1, 0, 1, and 2

2. Worksheet Key
4.2 - Graphing Linear Equations
12/6/2018 5:38 AM

3. Graphing Linear Equations
Section 4.2
4.2 - Graphing Linear Equations
12/6/2018 5:38 AM

4. Linear Equation in Two Variables
Standard Form: Ax + By = C
A, B, C are whole numbers and A and B both cannot be zero.
For it to be linear, the x has to be raised to the 1st power (exponent)

5. Is it linear?
x – 1.5y = –1.6
y = –2x
x + y2 = 9
x = 5
YES NO

6. Identifying from a table
Take the difference from the top to the bottom from the x and y’s
Do it for all of the points
If it is consistent, it is LINEAR. If it not consistent, then it NOT LINEAR.

7. Example 1
Is this table linear? x y –2 –7 –1 –5 –3 1 2

8. Example 2
Is this table linear? x y 3 2 1 4 6 –1 8 –2

9. Your Turn
Is this table linear? x y –3
–11 1 5 13 9 24 37

10. Graphing using a Table Plug in at least three x’s to obtain the y’s
One positive x-coordinate
Zero-coordinate
One negative x-coordinate
Connect the lines
Check

11. Example 1
Graph the linear equation, 2x + y = 5
Plug in –1 for x

12. Example 1
Graph the linear equation, 2x + y = 5
Plug in 0 for x

13. Example 1
Graph the linear equation, 2x + y = 5
Plug in 1 for x

14. Example 1
Graph the linear equation, 2x + y = 5 x y –1 7 5 1 3

15. Example 2
Graph the linear equation, –2x + 4y = 8 x y –2 2 –2 1 2 3

16. Your Turn
Graph the linear equation, –2x + y = –3 x y –2 2 –2 –7 –3 2 1

17. Example 3
Graph the linear equation, y = 3x x y –1 2 –1 –3 2 6

18. Your Turn
Graph the linear equation, y = –1/3x + 2 x y –3 6 –3 3 2 6

19. Example 4
Graph the linear equation, y = 2 x y –2 2 –2 2

20. Your Turn
Graph the linear equation, x = 2 x y –3 3 2 –3 3

21. Assignment
Worksheet