1. 1.4 Graphing linear Inequalities in Two Variables
Pg. 17

2. Checking Solutions 3x + 2y ≥ 2 true?
An ordered pair (x,y) is a solution if it makes the inequality true.
Are the following solutions to:
3x + 2y ≥ 2 true?
(0,0) (2,-1) (0,2)
3(0) + 2(2) ≥ 2
4 ≥ 2
Is a solution
3(0) + 2(0) ≥ 2
0 ≥ 2
Not a solution
3(2) + 2(-1) ≥ 2
4 ≥ 2
Is a solution

3. To sketch the graph of a linear inequality:
Sketch the line given by the corresponding equation
(solid if ≥ or ≤, dashed if < or >).
This line separates the coordinate plane into 2 half-planes.
Test points or just read the inequality.
Shade the half-plane that has the solutions to the inequality.

4. Slope Intercept Formula
The graph of an inequality is the graph of all the solutions of the inequality
3x+ 2y ≥ 2
Use Slope-intercept formula to graph.
Slope Intercept Formula
solid if ≥ or ≤
dashed if < or >

5. 3x+ 2y ≥ 2 3(0) + 2(0) ≥ 2 0 ≥ 2 Not a solution
Step 1: graph
the boundary (Line)
3x+ 2y ≥ 2
(the line is solid ≥)
Step 2: test a point
NOT on the line
(0,0) is always the easiest
If it’s Not on the line!!
3(0) + 2(0) ≥ 2
0 ≥ 2
Not a solution
So shade the other side of the line!!

6. Graph: y < 6

7. Graph: x 6

8. 4x – 2y < 7

9. The perimeter of a rectangle is to be more than 16 inches
The perimeter of a rectangle is to be more than 16 inches. Write an inequality describing the possible dimensions of the rectangle. Then graph the inequality and identify three possible solutions.
Use perimeter formula

11. Assignment
Pg 19, 1 – 27 odd
Pg 21, 1 – 25 odd