1. 7.2 Graphing Equations Objectives:
Learn to determine if an ordered pair is a solution of an equation.
Graph equations using ordered pairs.

2. How do you determine if an ordered pair is a solution??
You plug in the (x, y) value into your x and y in the equations and see if the right side = the left

3. Determine if the ordered pair is a solution of the equation.
y = 2x + 1
(3 , 7 )
7 = 2(3) + 1
YES
The ordered pair (3,7) is a solution.

4. Determine if the ordered pair is a solution of the equation.
4y - 3x = 22
(-2 , 4 )
4(4) – 3 (-2)= 22
= 22
YES
The ordered pair (-2,4) is a solution.

5. Determine if the ordered pair is a solution of the equation.
y - 3x = -2
(-2 , 8 )
(8) – 3 (-2)= -2 ???
8 + 6  -2 NO
The ordered pair (-2,8) is not a solution.

6. Graphing Equations
We are going to learn three ways to graph a linear equation. Today we are going to learn how to graph by “Making a Table”

7. Making a Table Solve the equation in y = format (slope intercept form)
Pick your x values (-1, 0,1)
Plug in the x values into x in the equation to find the corresponding y values
Plot the (x, y) ordered pairs on the coordinate plane

8. y
Graph:
y = x y x x

9. y Find 3 solutions y = 2x + 1 x 1 3 (1,3) 1 (0,1) -1 -1 (-1,-1)
X Values
Y=2x + 1
Y Values
(x,y) 1 3
(1,3)
2(1) +1 1
2(0) +1
(0,1) -1
2(-1) +1
(-1,-1) -1

10. Solve for ‘y’
Solve for ‘y’ means “get y all by itself”

11. y x 1 2(1) +5 7 (1,7) 2(0) +5 5 (0,5) -1 2(-1)+5 3 (-1,3) -2x + y = 5
Graph:
-2x + y = 5
y = 2x + 5 x X
Y=2x +5 Y
(x,y) 1
2(1) +5 7
(1,7)
2(0) +5 5
(0,5) -1
2(-1)+5 3
(-1,3)

12. y x Y=2/3x +5 3 7 5 -3 3 3y = 2x + 15 (3,7) Graph: -2x + 3y = 15 (0,5)
(2/3)(3) +5 5
(2/3) (0) +5
(0,5) -3 3
(2/3)(-3)+5
(-3,3)

13. y
Graph:
3x - y = 2 y x
3x = y + 2
3x - 2 = y x

14. Assignment: Page 311 (2-26) even -Use graph paper - #’s 8-14 just make the table you do not have to graph -#’s make the table and graph