Transcript Lesson 2.8 - Crestwood Local Schools

Inequalities and Their Graphs
PRE-ALGEBRA LESSON 2-8
(For help, go to Lesson 1-4.)
Bell Work #11
Graph each set of numbers on a number line. Order the numbers from least
to greatest.
1. –3, 7, –9
2. –2, –10, –8
3. 0, 3, –5
4. 3, –6, 10
Check Skills You’ll Need
2-8
Inequalities and Their Graphs
PRE-ALGEBRA LESSON 2-8
Solutions
1.
–9, –3, 7
2.
–10, –8, –2
3.
–5, 0, 3
4.
–6, 3, 10
2-8
Inequalities and Their Graphs

PRE-ALGEBRA LESSON 2-8
Vocabulary
inequality
An ____________________
is a mathematical sentence that contain >, <
,
,
, or
Any number that makes the inequality
A solution of an inequality is ____________________________________________
___________________________________________________________________
true
2-8
Inequalities and Their Graphs
PRE-ALGEBRA LESSON 2-8
Graph the solutions of each inequality on a
number line.
a. x > –2
An open dot shows that –2 is not a solution.
Shade all the points to the right of –2.
b. w >
– –5
A closed dot shows that –5 is a solution.
Shade all the points to the right of –5.
2-8
Inequalities and Their Graphs
PRE-ALGEBRA LESSON 2-8
(continued)
c. k <
–4
A closed dot shows that 4 is a solution.
Shade all the points to the left of 4.
d. y < 6
An open dot shows that 6 is not a solution.
Shade all the points to the left of 6.
2-8
Quick Check
Inequalities and Their Graphs
PRE-ALGEBRA LESSON 2-8
Write the inequality shown in each graph.
a.
x >
– –3
b.
x<3
Quick Check
2-8
Inequalities and Their Graphs
PRE-ALGEBRA LESSON 2-8
Food can be labeled very low sodium only if
it meets the requirement established by the federal government.
Use the table to write an inequality for this requirement.
Label
Definition
Sodium-free food
Less than 5 mg per serving
Very low sodium food
At most 35 mg per serving
Low-sodium food
At most 140 mg per serving
2-8
Inequalities and Their Graphs
PRE-ALGEBRA LESSON 2-8
(continued)
Words
a serving of very
low sodium food
Let
Equation
v
=
v
has at most
35 mg sodium
number of milligrams of sodium in a serving of
very low sodium food.
<
–
35
Quick Check
2-8
Inequalities and Their Graphs
PRE-ALGEBRA LESSON 2-8
1. Graph –7 >
– w.
2. Write an inequality for the graph.
x > –30
3. A child must be at least 50 in. tall to ride on the roller coaster. Write an
inequality for this situation.
h>
– 50
2-8