Name_________________________
Date___________
CC Algebra Lesson-40 Systems of Linear Inequalities
Ms. Socci
To Find the Solution Set of a System of Linear Inequalities:
 Solve each inequality for y
 Graph each inequality (Make sure you have solid or dotted lines)
 Shade the correct region for each graph
 Label the common region shaded by both graphs with a capital letter
S for solution
 *If they do not overlap, there is no solution.
Example: Graph the following system of
inequalities and label the solution set S:
y>x+4
x+y<0
State a point in the solution
System of Inequalities:
Solution:
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Example:
You have at most 8 hours to spend at the mall and at the beach. You want to spend at
least 2 hours at the mall and more than 4 hours at the beach. Write and graph a
system that represents the situation. How much time can you spend at each location?
Practice:
1) x + y > 3
x–y<6
State a point in the solution
2) y + 3x > 6
y < 2x - 4
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State a point in the solution
3) y < 2x – 3
y>
−2
3
𝑥+2
State a point in the solution
4)
x + 2y < 8
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y<x+4
State a point in the solution
5)
6)
Common Core
1. A clothing manufacturer has 1,000 yd. of cotton to make shirts and pajamas. A shirt
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requires 1 yd. of fabric, and a pair of pajamas requires 2 yd. of fabric. It takes 2 hr. to
make a shirt and 3 hr. to make the pajamas, and there are 1,600 hr. available to make
the clothing.
i. What are the variables?
ii. What are the constraints?
iii. Write inequalities for the constraints.
iv. Graph the inequalities and shade
the solution set.
v. What does the shaded region
represent?
vi. Suppose the manufacturer makes
a profit of $10 on shirts and $18 on
pajamas. How would it decide
how many of each to make?
vii. How many of each should the manufacturer make, assuming it will sell all the
shirts and pajamas it makes?
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2. The graph of an inequality is shown below.
a) Write the inequality represented by the graph.
b) On the same set of axes, graph the inequality
.
c) The two inequalities graphed on the set of axes form a system. Oscar thinks that the point
is in the solution set for this system of inequalities. Determine and state whether you
agree with Oscar. Explain your reasoning.
3. Connor wants to attend the town carnival. The price of admission to the carnival is $4.50,
and each ride costs an additional 79 cents. If he can spend at most $16.00 at the carnival,
which inequality can be used to solve for r, the number of rides Connor can go on, and
what is the maximum number of rides he can go on?
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4. A high school drama club is putting on their annual theater production. There is a
maximum of 800 tickets for the show. The costs of the tickets are $6 before the day of the
show and $9 on the day of the show. To meet the expenses of the show, the club must
sell at least $5,000 worth of tickets.
a) Write a system of inequalities that represent this situation.
b) The club sells 440 tickets before the day of the show. Is it possible to sell enough
additional tickets on the day of the show to at least meet the expenses of the show?
Justify your answer.
5. Which graph represents the solution of
1)
and
?
2)
3)
4)
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6. On the set of axes below, graph the inequality
7. Solve for x algebraically:
8. If x is a number in the interval
, state all integers that satisfy the given inequality.
Explain how you determined these values.
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9. Albert says that the two systems of equations shown below have the same solutions.
Determine and state whether you agree with Albert. Justify your answer.
10. An on-line electronics store must sell at least $2500 worth of printers and computers per
day. Each printer costs $50 and each computer costs $500. The store can ship a
maximum of 15 items per day. On the set of axes below, graph a system of inequalities
that models these constraints.
Determine a combination of printers and computers that would allow the electronics store to
meet all of the constraints. Explain how you obtained your answer.
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11. Edith babysits for x hours a week after school at a job that pays $4 an hour. She has
accepted a job that pays $8 an hour as a library assistant working y hours a week. She
will work both jobs. She is able to work no more than 15 hours a week, due to school
commitments. Edith wants to earn at least $80 a week, working a combination of both
jobs. Write a system of inequalities that can be used to represent the situation. Graph
these inequalities on the set of axes below.
Determine and state one combination of hours that will allow Edith to earn at least $80 per
week while working no more than 15 hours.
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