Page 331 - Algebra 1

Writing an Inequality from a Graph
Write an inequality for each graph.
Example
3
a.
-3 -1 1 SOLUTION
b.
endpoint: –1 k >-1
inequality: >
inequality: <
SOLUTION
endpoint: 25 n ≥ 25
inequality: ≥
180
inequality: ≤
5 15 25 35 40
c.
0 _1 _1 _3 1 424
d.
SOLUTION
endpoint: _3 4
r < _3 4
SOLUTION
endpoint: 150 z ≤ 1 5 0
Application: Practice Time
120 150
Example
4
Marie does not take a break until she has practiced playing the violin for at least half an hour.
a. Write an inequality to represent the number of hours that Marie must practice before she takes a break.
SOLUTION Let h represent the number of hours that Marie practices. The phrase “at least” can be represented with ≥.
h ≥ 0.5
b. Graph the solution set of the inequality.
SOLUTION Identify the endpoint (0.5), determine if the circle is open or closed (closed), and the direction in which the arrowhead points (to the right).
-1 0 1
a. Determine which of the values {-2, 0, 5, 11} are part of the solution set (Ex 1) of the inequality 3x + 4 < 19.
Graph each inequality. b. u > -2
(Ex 2)
c. t≥2.5 (Ex 2)
Math Reasoning
Analyze Although the graph of an inequality for a problem-solving situation includes a wide range of values, the problem will create some restrictions. What restrictions would be placed on this problem?
Lesson Practice
316 Saxon Algebra 1