Luttrell 2012
76
Name: ______________________
Date: _____
5c – Number Line
Real numbers can be plotted on a line from left to right with the numbers in ascending order.
That means negatives are placed on the left end and positives on the right. Remember -100 is
smaller than -1, so -100 would be further left than -1. For equalities, a solid dark dot on the
number line indicates the value of the variable that makes the equation true. For example, an
equation is found that
x
= 4. The graph of
x
= 4 is shown below:
| | | | | | | |
-2 -1 0 1 2 3 4 5 6
Below are examples of inequalities and their solutions graphed. Remember that the inequality
symbols switch when multiplying (dividing) by a negative. Also an open circle or ) shows a
strict inequality, as in the constant is not included in the solution set. On the other hand, a closed
circle or ] shows that the constant is included.
E
x
ample: 4
x
- 1 < 7
-
x
-
2 ≥ 2
4
x
< 8
-
x
≥ 4
x
< 2
x
≤- 4
| | | |
◯
| | | |
| | | | | | |
-2 -1 0 1 2 3 4 5 6 -6 -5 - 4 -3 -2 -1 0 1
Solve and graph the solution on a number line:
1. 3
x
- 2 = 13
2. 2
x
+ 2 = 12
3. (4 - 2)
x
= 12
4. -
4 ≤
x
-
1 ≤1
5. -3
w
< 12
6. 6(1 -
x
) - 3
x
≤ 12
7. -2
z
> 12
8. 2
y
≥-11
9. 3
x
+ 4 > 5
