1. 1.2.2 Warm-up
Two people can balance on a seesaw even if they are different weights. The balance will occur when the following equation, w1d1 = w2d2, is satisfied or true.
Eric and his little sister Amber enjoy playing on the seesaw at the playground. Amber weighs 65 pounds. Eric and Amber balance perfectly when Amber sits about 4 feet from the center and Eric sits about
2.5 feet from the center.
About how much does Eric weigh?

2. w1d1 = w2d2
w2 = x
d2 = 2.5
w1 = 65
d1 = 4
(65)(4) = x(2.5)
x = 104
Eric weighs 104 lbs.

3. Writing Inequalities
in one variable

4. Inequalities infinite not not ≤,≥,<,> and ≠ Solution sets
Lesson Creating Equations and Inequalities in one variable
____________________are similar to equations in that they are mathematical sentences. They are different in that they are not equal all the time. An inequality has __________________solutions, instead of only having one solution like a linear equation. Setting up the inequalities will follow the same process as setting up the equations did. Solving them will be similar
Inequalities
infinite
not
The prefix in in the word inequality means _____________. Inequalities are sentences stating that two things are ____________ equal.
_________________________________________are used with inequalities.
______________________________________are values that make a sentence or statement true.
not
≤,≥,<,> and ≠
Solution sets

5. Symbol Example Solution Set > x > 3 ≥ x ≥3 < Less than
Description
Example
Solution
Set
>
Greater than, more than
x > 3
All numbers greater than 3; does not include 3 ≥
Greater than or equal to,
at least
x ≥3
All numbers greater than or equal to 3; includes 3
<
Less than
x < 3
all numbers less than 3; does not include 3 ≤
Less than or equal to, no more than
x ≤ 3
All numbers less than or equal to 3; includes 3 ≠
Not equal to
x ≠ 3
includes all numbers except 3
Symbol Description Example Solution Set

6. REMEMBER!
Multiplying or dividing both sides of an inequality by a negative value requires flipping the inequality symbol.

7. Look at the example of the inequality 2 < 4.
Multiply both sides by –2
2(–2) < 4(–2) or –4 < –8
Is the statement true?
NO!
To make the statement true, you must ___________ the inequality symbol: –4 > –8
reverse

8. Example 6: Juan has no more than $50 to spend at the mall
Example 6: Juan has no more than $50 to spend at the mall. He wants to buy a pair of jeans and some juice. If the sales tax on the jeans is 4% and the juice with tax costs $2, what is the maximum price of jeans Juan can afford?
Answer: x x + 2 ≤ 50

9. Answer: Alexis needs to work at least 58.3 hours
Example 7: Alexis is saving to buy a laptop that costs $1,100. So far she has saved $400. She makes $12 an hour babysitting. What’s the least number of hours she needs to work in order to reach her goal?
Answer: Alexis needs to work at least 58.3 hours

10. Answer: more than 18 hours or more than 6 days
Example 8: A radio station is giving away concert tickets. There are 40 tickets to start. They give away 1 pair of tickets every hour for a number of hours until they have at most 4 tickets left for a grand prize. If the contest runs from 10:00A.M. to 1:00 P.M. each day, for how many days will the contest last?
Answer: more than 18 hours or more than 6 days