Warmups

Graph:

1. x – 3y = 6

2. y = -2x + 4

3. y – 3 = 1(x + 2)

4. y = -2

5. x = 4

Working backwards…

Given the graph, you come up with inequality involving absolute value…

|x-middle #| Distance to middle

and?

or?

TOO

Given the graph, you come up with inequality involving absolute value…

|x-middle #| Distance to middle

and?

or?

7-8 Graphing Inequalities with 2

Variables

Objective: To graph an inequality on a coordinate plane.

Steps to Graphing Inequalities

1. Dotted or Solid Line?

2. Graph line as if it said “=“

*Review graphing see Chapter 6*

3. Choose a test point that is not on the line

*Usually (0,0)

4. Shade appropriate side

*If “true” shade where test point is

*If “false” shade opposite side

< or > < or >

Write on “Notes” Paper

1. y < -2x + 3

1) Dotted

2) b = 3, m = -2

3) (0,0)

0 < -2(0) + 3

0 < 0 + 3

0 < 3

4) True(Shade this side)

2. 4x + 2y > 8

1) Solid

2) (2,0) (0,4)

3) (0,0)

4(0) + 2(0) > 8

0 + 0 > 8

0 > 8

4) False

(Shade this side)

3. 2x – 3y < 12

1) Dotted

2) (6,0) (0,-4)

3) (0,0)

2(0) - 3(0) < 12

0 + 0 < 12

0 < 12

4) True

(Shade this side)

4. y > 3x

1) Dotted

2) b = 0, m = 3/1

3) (1,1)

1 > 3(1)

1 > 3

4) False

(Shade this side)

5. y < -3

1) Solid

2) y = -3

3) (0,0)

0 < -3

4) False

(Shade this side)

6. y – 2 < -1/2(x + 4)

1) Solid

2) (-4,2) m = -1/2

3) (1,1)

1 -2 < -1/2(1 + 4)

-1 < -1/2(5)

-1 < - 2.5

4) False(Shade this side)

TOO

1. 3x – y > 6

2. y < -3/4x + 5

Homework

Pg. 440 #23-37 odd