1. Lesson Objective: I will be able to …
Solve one-step inequalities in one variable by
using multiplication
using division
Language Objective: I will be able to …
Read, write, and listen about vocabulary, key
concepts, and examples

2. Page 14

3. Page 14

4. Example 1: Multiplying or Dividing by a Positive Number
Page 15
Solve the inequality 7x > -42 and graph the solutions.
>
Since x is multiplied by 7, divide both sides by 7 to undo the multiplication.
1x > –6
x > –6
–10 –8 –6 –4 –2 2 4 6 8 10

5. Example 2: Multiplying or Dividing by a Positive Number
Page 16
Solve the inequality and graph the solutions.
Since r is multiplied by , multiply both sides by the reciprocal of .
r < 16 2 4 6 8 10 12 14 16 18 20

6. Solve the inequality and graph the solutions.
Your Turn 2
Page 16
Solve the inequality and graph the solutions.
Since m is divided by 3, multiply both sides by 3 to undo the division.
3(2.4) ≤ 3
7.2 ≤ m
(or m ≥ 7.2) 2 4 6 8 10 12 14 16 18 20

7. Page 15

8. Important!
If you multiply or divide of an inequality by a negative number, you must reverse the inequality to make the statement true.
Example: Solve the inequality -12x > 84.
Divide both sides by -12.
>
x > -7
Check solution: x can equal -5 since -5 > -7.
-12(-5) > 84
60 > 84, but this is FALSE!
Since x was divided by a negative number, we must change > to <.
So x < –7 is the answer.

9. Caution!
Do not change the direction of the inequality symbol just because you see a negative sign. For example, you do not change the symbol when solving 4x < –24.

10. Example 3: Multiplying or Dividing by a Negative Number
Page 16
Solve the inequality and graph the solutions.
Since x is divided by –3, multiply both sides by –3. Change to .
24  x
(or x  24) 16 18 20 22 24 10 14 26 28 30 12

11. Solve the inequality 10 ≥ -x and graph the solutions.
Your Turn 3
Page 17
Solve the inequality 10 ≥ -x and graph the solutions.
–1(10) ≥ –1(–x)
Multiply both sides by –1 to make x positive. Change  to .
–10 ≤ x
–10 –8 –6 –4 –2 2 4 6 8 10

12. Homework
Assignment #4
Holt 3-3 #5-10, 42, 57-60