≥
>
˂
Intro to
Inequalities
≤
Credit Card
Situation 1: Your mom gave you her credit card
and said that you could go shopping for a
birthday present for your girlfriend (or
boyfriend). She said that you could spend
no more than $125.
1. List at least 5 of the amounts that you could
spend.
2. You saw an awesome cell phone that was priced
at $130? Can you buy it?
Explain your thinking.
Credit Card
Situation 1: Your mom gave you her credit card
and said that you could go shopping for a
birthday present for your girlfriend (or
boyfriend). She said that you could spend
no more than $125.
3. What is the maximum amount that you could
spend on the present and still be following your
mom's instructions?
4. Is there just one correct amount that you could
spend?
Credit Card
Situation 1: She said that you could spend no
more than $125.
What other words could we use for this?
No more
than 125
Maximum
of 125
Up to 125
Less than or
equal to 125
Using Inequality symbols helps to represent all the
possibilities that you could spend.
Symbolic:
spending (x)
125
x ≤ 125
same as
125 ≥ x
Credit Card
Situation 2: What if your mom said that you
had to spend at least $125 on the present.
1. List no less than 4 of the possibilities that
you could spend.
2. What is the least you could spend on the
present and still be following your mom's
instructions?
3. What is the most you could spend on the
present and still be following your mom's
instructions?
Credit Card
Situation 2: What if your mom said that you
had to spend at least $125 on the present.
What other words could we use for this?
At least 125
Minimum
of 125
125 or more
Greater than
or equal to
125
Symbolic:
spending (x)
125
x ≥ 125
same as
125 ≤ x
Fill in each column with phrases that
best describe the inequality
<
<
>
>
LESS THAN
LESS THAN OR
EQUAL TO
GREATER
THAN
GREATER THAN
OR EQUAL TO
BIGGER
THAN
MINIMUM OF
SMALLER
THAN
MAXIMUM OF
UP TO
NO MORE
THAN
AT MOST
AT LEAST
NO LESS THAN
NAME THAT NUMBER
What is a compound inequality?
____________________________
___________________________________
___________________________________________.
Situation 3: Contestants on American idol must be between
the ages of 15 and 28.
1. List at least 5 of the ages a contestant could be.
Situation 3: Contestants on American
idol must be between the ages of
15 and 28.
2. What is the youngest you could be and how could you
describe that as an inequality?
3. What is the oldest you could be and how could you
describe that as an inequality?
4. How could you write this situation using inequalities?
Write inequalities based on the
situations below:
1)
2)
3)
4)
5)
6)
7)
8)
Jason can spend up to $95 on his Dad’s credit card
Ella must have an 85 or over in MMA to get her car back
Dana must not fail more than 2 classes this year in order to
graduate
Sam needs to score better than 98 on his next English quiz to get
an A average
Angel cannot spend more than 2 and a half hours on her
homework
John may watch up to half an hour of TV per day
If Aaron uses more than 600 minutes on his cell phone each
month, he pays a $20 penalty
Catherine has to smile 5 or more times a day at work in order to
get a $100 bonus
Homework


Pg. 171 #1-5, 18-21, 34-37, 46-49
Pg. 206 #2, 15, 28, 30-35
Inequality symbols allow us to
represent situations that have
___________________________.
You use them instead of
___________________________.
What is a solution to an inequality?
____________________________
_______________________.
Try It
1. You can receive a maximum of 3 absences to exempt the final exam.
numbers_______, _______, _______ Inequality____________________
2. Your semester average for the class needs to be at least an 80 to exempt
the final exam.
numbers_______, _______, _______ Inequality____________________
3. To pass Algebra you can have no less than a 70 average for the entire
school year.
numbers_______, _______, _______ Inequality____________________
4. To ride on the roller coaster, Texas Cyclone, you must be taller than 40
inches.
numbers_______, _______, _______ Inequality____________________