Transcript Slide 1

Which is worth more?
Four $10 bills?
Six $5 bills
or
Six $5 bills = $30
Four $10 bills = $40
So, Four $10 bills is worth more.
How do we say this mathematically?
$40 is greater than $30…
or
$40 > $30
We can also say….
$30 is less than $40
or
$30 < $40
We call these
INEQUALITIES
What are the inequality signs?
>
greater than
>
<
less than
<
greater than or equal to
less than or equal to
How do we write and graph inequalities?
A number, x, is greater than 3.
x>3
or
Next, how do we graph this?
3<x
Steps to Graphing Inequalities
1. Draw a number line (with numbers!).
2. Place a dot on the numbers.
Closed circle indicates equal to (> or <)
Open circle indicates not equal to (< or >)
3. Draw an arrow in the direction of all possible numbers
-6 -5
-4
-3 -2
-1
0
1
2
3
4
5
6
7
Graph x < 2
Draw an open – circle at 2.
What numbers are less than 2 ?
-2
-1
Draw an arrow towards 1, 0, -1, etc.
-6 -5
-4
-3 -2
-1
0
1
2
3
4
5
6
7
0
1
Graph x > -3
Draw an closed circle at -3
What numbers are greater than -3 ?
-2
Draw an arrow towards -2, -1, 0, 1 etc.
-6 -5
-4
-3 -2
-1
0
1
2
3
4
5
6
7
-1
0 1
Now, it’s time to play…..
Which is the correct graph for x < 4 ?
A
-6 -5
-4
-3 -2
-1
0
1
2
3
4
5
6
7
B
-6 -5
-4
-3 -2
-1
0
1
2
3
4
5
6
7
-6 -5
-4
-3 -2
-1
0
1
2
3
4
5
6
7
C
D
-6 -5
-4
-3 -2
-1
0
1
2
3
4
5
6
7
The correct answer is…..
D
-6 -5
-4
-3 -2
-1
0
1
2
3
4
5
6
7
Which is the correct inequality for the following graph?
-6 -5
-4
-3 -2
-1
0
1
2
3
4
5
A
x < -1
B > -1
C
x < -1
D > -1
6
7
Find the graph that matches the
inequality