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440 Algebra
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© W
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up/M
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raw
-Hill
Questions on SPUR ObjectivesSee pages 650–653 for objectives.
Lesson Master
REPRESENTATIONS Objective I
1. Refer to the graph at the right.
a. What system is represented?
b. What is the solution?
c. Verify your answer to part b.
2. Refer to the graph at the right.
a. What system is represented?
b. What is the solution?
c. Verify your answer to part b.
In 3–5, a system is given. Solve the system by graphing.
3. y - 3x = −4
y = 2x - 1
4. 3x + 6y = 0
y = 4x + 9
5. 2x - 6y = −5
y = 4x −1
10-1B
x
y
1-1-2-3-4-5-6-7-8
1
-1
-2
-3
-4
-5
-6
-7
-8
2
4
5
6
7
8
2 3 4 5 6 7 8
x
y
1-1-2-3-4-5-6-7-8
1
-1
-2
-3
-4
-5
-6
-7
-8
2
4
5
6
7
8
9
10
3 4 5 6 7 8
x
y
x
y
x
y
Back to Lesson 10-1 Answer Page
Algebra 441
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page 210-1B
In 6–8, a system is given. Solve the system by graphing.
6. y = 4x + 14
y = 2x + 10
7. y = −x + 7
y = 1 __
2 x + 1
8. 3x - 4y = 3
4y = x -9
In 9 and 10, a situation is described. a. Translate the information into two equations. b. Use a
calculator table to ! nd a good window to display the graph. What window did you use? c. Use the
graph from Part b to answer the question.
9. A coin jar contains only nickels and quarters. There are exactly 38 coins
in the jar, and the total value of the coins is $2.50.
a. Let x = the number of nickels in the jar.
Let y = the number of quarters in the jar.
b.
c. How many of each kind of coin is in the jar?
10. A tomato plant 6 centimeters tall is growing at a rate of 4 centimeters
per day. Another tomato plant 10 centimeters tall is growing at a rate of
2 centimeters per day.
a. Let x = the number of days the plant has been growing.
Let y = the height of the plant after x days.
b.
c. After how many days will the plants be the same height?
How tall will they be?
x
y
x
y
x
y
SMP08ALG_NA_TR2_C10.indd 441 5/31/07 10:46:04 AM
Back to Lesson 10-1 Answer Page
Algebra 443
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Lesson Master10-2B
SKILLS Objective A
In 1–8, a system is given. Use substitution to ! nd the solution.
1. y = 3x
y = −x + 4
2. b = 2a + 5
b = a + 3
3. y = 3x + 1
y = 0.5x - 4
4. y = 2x - 5
y = −2x + 7
5. y = 1 __
2 x
y = 3x + 4 6.
d = 1 __ 3 c + 7
d = 2 __ 3 c + 8
7. y = 1 __
2 x + 5
y = −4x - 4 8.
y = 0.4
y = 0.2x + 6
Questions on SPUR ObjectivesSee pages 650–653 for objectives.
Back to Lesson 10-2 Answer Page
444 Algebra
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page 2
USES Objective G
9. Carl is 0.2 mile ahead of Andrea on his bicycle. Andrea rides at 15 mph
on the same road trying to catch up to him. Carl rides at a rate of 10
mph. Their father is also riding his bike on the same road and reaches
Andrea in 5 minutes. Solve a system of equations to fi nd out if their
father reaches Andrea before she catches up to Carl.
10. Car rental A costs $20 per day and $0.10 per mile and care rental B
costs $15 per day and $0.20 per mile. Solve a system of equations to
fi nd the distance for which the costs are the same on a one-day
rental.
11. Suppose a school has 1,200 students and is growing at a rate of 100
students per year. The neighboring school has 1,000 students and is
growing at a rate of 150 students per year. After how many years will
the schools have the same number of students? How many students will
they each have?
12. At a Mexican take-out restaurant one family ordered 5 burritos and 4
tacos. The burritos and tacos cost $17.50, not including tax. Another
family ordered 9 burritos and 5 tacos. Their burritos and tacos cost
$27.65 before tax. What is the cost of 1 burrito at this restaurant? What
is the cost of 1 taco?
10-2B
SMP08ALG_NA_TR2_C10.indd 444 5/31/07 10:46:22 AM
Back to Lesson 10-2 Answer Page
446 Algebra
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Questions on SPUR ObjectivesSee pages 650–653 for objectives.
Lesson Master
SKILLS Objective A
In 1–10, a system is given. Solve each system by substitution.
1. x = 2y - 4
3x - 5y = −11
2. g = 2h + 3
4g - 3h = −3
3. n = 4m - 10
2n - 3m = 0
4. y = 0.4z - 2.4
4y - 10z = −18
5. a + 7b = 49
b = 7 + a
6. 4y - 2x = 2
x = 2 __
3 y
7. 0.2c - 0.4d = −0.4
c = d - 2
8. 3x - y = −2
y = 2x + 12
9. x - y = 5
2x + y = 1
10. b = −2a + 2
a = b + 7
10-3B
Back to Lesson 10-3 Answer Page
Algebra 447
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page 210-3B
SKILLS Objective A
11. To help Kyle study for a test, Cary 2x - 6y = 8
8x - 2y = 10
2x - 6y = 8
x =
6y + 8 _____
2
asked him to solve the system
Kyle’s solution was (1, -1). Check his
solution by fi lling in the missing portions at x =
the right. Was Kyle’s solution correct? 8( ) - 2y = 10
- 2y = 10
22y + 32 = 10
22y =
y = and
x =
USES Objective G
12. Students having a brownie and cookie sale sold 38 items and earned a
total of $47.25. They sold brownies for $1.50 each and cookies for $0.75
each.
a. Let b = the number of brownies they sold and c = the number
of cookies they sold. Write a system of equations for this situation.
b. How many cookies did they sell? How many brownies did they sell?
13. A teacher is writing a test that is worth 100 points. Some of the
questions are worth 4 points each and the rest of the questions are
worth 5 points each. There is a total of 23 questions on the test.
a. Describe the situation with a system of equations.
b. How many of each kind of question is on the test?
SMP08ALG_NA_TR2_C10.indd 447 5/31/07 10:46:37 AM
Back to Lesson 10-3 Answer Page
Algebra 449
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Lesson Master
SKILLS Objective B
In 1–8, a system is given. Solve the system using addition.
1. 3x - 2y = −5
4x + 2y = −16
2. 3r - 5s = −7
−3r + 2s = 1
3. 2m - n = 4
1.2m - 0.3n = 1.5
4. x - y = − 1 __
5
10x + 5y = 7
5. 3a - 2b = −8
−3a + 4b = 16
6. 1
__ 2 m - n = −30
m + n = 15
7. 2a + b = −80
−3a + b = 120
8. 4x - 2y = 0
4x + y = 0
10-4B Questions on SPUR ObjectivesSee pages 650–653 for objectives.
Back to Lesson 10-4 Answer Page
450 Algebra
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page 2
9. The ordered pair (H, K) = (134, 256) is the solution to the system of
equations 5H + 6K = 2,206
-8H + 3K = −304
. Check the solution in both equations.
10. Is (x, y) = (−100, 3) a solution to the system of equations
4x - 2y = −406
3x + 5y = −315
? Explain.
USES Objective G
11. Two people paddle a canoe 8 miles upstream in two hours. Then they
turn around and paddle 8 miles downstream in one hour. If they are
paddling at the same rate both upstream and downstream, how fast are
they paddling? How fast is the current?
12. A family has adopted a total of 13 cats and dogs from the local animal
shelter. The number of cats they have is 2 less than twice the number of
dogs. How many cats and dogs do they have?
13. At a furniture store, you can purchase 2 fl oor lamps and 3 table lamps
for $360, or 3 fl oor lamps and 1 table lamp for $330. What is the cost of
one fl oor lamp? What is the cost of one table lamp?
14. On a lunch menu, a turkey sandwich with a cup of soup is $6.00 and a
half of a turkey sandwich with a cup of soup is $3.75. Assuming the half
sandwich costs exactly half as much as the whole sandwich, how much
does the cup of soup cost?
10-4B
SMP08ALG_NA_TR2_C10.indd 450 5/31/07 10:47:11 AM
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452 Algebra
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Questions on SPUR ObjectivesSee pages 650–653 for objectives.
Lesson Master
SKILLS Objective B
1. Consider the system 3x - 2y = −5
6x - 3y = −12
.
a. What operation was done to the system to
get −6x + 4y = 10
6x - 3y = −12
?
b. Solve the system.
2. Consider the system 2c + 8d = 68
4c - 2d = 28
.
a. If the second equation in the system is multiplied
by 4, then adding the equations will eliminate
what variable?
b. Solve the system.
3. Consider the system 2x - y = −13
3x + 2y = −2
.
a. If the fi rst equation in the system is multiplied
by 2, then adding the equations will eliminate
what variable?
b. Solve the system.
In 4–6, solve the system.
4. −3x + y = 8
x - 2y = −1
5. 4y - x = 8
y + 2x = 2
6. 2a - 5b = 31
8a + b = 19
10-5B
Back to Lesson 10-5 Answer Page
Algebra 453
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page 2
In 7–9, solve the system.
7. 1 _ 2 m + 3 _ 2 n = −5
7 _ 2 m - 5 _ 2 n = 43
8. 0.5x - 0.2y = 0
0.4x + 0.8y = 0
9. 4 _ 5 x + y = 1
2x - 10
__ 3 y = -1
USES Objective G
10. The difference of the smaller of two integers and twice the larger
integer is −7. The sum of −3 times the smaller integer and 5 times the
larger integer is 18. What are the two integers?
11. At an ice cream store, one family bought three medium ice cream cones
and two sundaes for $9. Another family bought fi ve medium cones and
one sundae for $9.75. What is the cost of a sundae and what is the cost
of a medium ice cream cone at the store?
12. At a dog park, an observer noticed that, counting all of the dogs and
people, there were 80 legs and 25 heads in the crowd. How many dogs
were at the park? How many people were at the park?
13. At a library book sale, paperback books cost $0.50 each and hardback
books cost $1.25 each. At the sale, they sold 80 books and made $62.50.
How many paperback books did they sell? How many hardback books
did they sell?
10-5B
SMP08ALG_NA_TR2_C10.indd 453 5/31/07 10:47:25 AM
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Algebra 455
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Lesson Master
PROPERTIES Objective F
In 1–6, describe the graph of the given system as intersecting lines, parallel
lines, or coincident lines.
1. 2x - 3y = −18
y = 4x + 16
2. 2x + 3y = 4
−4x - 6y = 6
3. y = 5x
4x - 5y = 0
4. 2x + 6y = 12
y = − 1 __
3 x + 2
5. y
__ 2 = 5 __
2 x - 3
10x - 2y = 4 6.
3x - 4y = 7
y = 3 __ 4 x - 7 __
4
7. Find the value of k so the graphs of the equations in the system
4y - 2x = 12
2y = kx - 8
are parallel lines.
8. Find the value of k so the graphs of the equations in the system
4y + 3x = 1
12y = kx + 3
are coincident lines.
9. True or false. If a = −10, the system 4x - 5y = 6
8x + ay = 12
will have infi nitely
many solutions.
10. True or false. If a = 3, the system 2x + 2y = 3
4x + ay = 1
will have
no solution.
10-6B Questions on SPUR ObjectivesSee pages 650–653 for objectives.
Back to Lesson 10-6 Answer Page
456 Algebra
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page 2
USES Objective G
11. During a recent store sale, all shirts were priced at $15 each, and shoes
were priced at $15 per pair. Molly reported that they sold 19 items total,
and Gus reported that they sold $300 worth of merchandise. Can both
Molly and Gus be correct? Explain.
12. Penny buys 2 cans of soup and 4 bags of grapes at the grocery store for
$16. Then she fi nds out they are having a 10% off sale on those items
the next day. She returns the next day and buys 1 can of soup and 2
bags of grapes, and the clerk tells her that her total after the discount is
$8.10. Did the clerk calculate correctly?
REPRESENTATIONS Objective I
In 13–15, match each system of equations to its corresponding graph
and state the number of solutions. Each system is graphed in the
standard window.
13. y - 3x = 0
3x -y = 3
14. x - y = 2
2x + y = 7
15. 2x + 3y = 6
y = − 2 __
3 x + 2
A B C
10-6B
SMP08ALG_NA_TR2_C10.indd 456 5/31/07 10:47:41 AM
Back to Lesson 10-6 Answer Page
464 Algebra
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Questions on SPUR ObjectivesSee pages 650–653 for objectives.
Lesson Master
USES Objective H
1. You set a spending limit of $600 for birthday gifts for your family and
friends this year. You will buy presents for 6 family members and 4
friends. You decide you want to spend at most $10 more on family
members than on friends. You will also spend the same amount for each
family member and the same amount for each friend.
a Write a system of inequalities that b. Graph the inequalities to show how much
describes the amount that you can spend you can spend on a family gift and on gift
on a gift for a family member x and on a for a friend.
gift for a friend y.
c. What is the maximum amount you can spend
on a gift for a family member?
d. What is the maximum amount you can spend
on a gift for a friend if you spend the maximum
on a family gift?
2. In a mountain bike relay race, together Nikki and Daronelle rode less
than 18 miles. Nikki rode at a slower rate than Daronelle. Daronelle rode
for 3 hours and Nikki rode for 2 hours.
a. Write a system of inequalities that b. Graph all combinations of possible rates
describes the rate d in miles per hour that for Daronelle and Nikki during the
Daronelle rode and the rate n in miles per bike race.
hour that Nikki rode.
c. What is the maximum rate at which
Daronelle could have ridden?
d. How far did Daronelle ride if she rode at
her maximum rate?
10-9B
x
y
d
n
Back to Lesson 10-9 Answer Page
Algebra 465
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page 2
REPRESENTATIONS Objective J, K
In 3–8, graph the solution to the system.
3. y < 2x + 1
y ≥ −4
4. 3x + y < −1
3x - 4y > 12
5. x ≤ −2
x + y >1
6.
y < 4x
x ≤ 1
y ≤ −2 7.
−2x + 3y < 6
x ≤ 4
y > −x - 2 8.
y > 1 __ 2 x - 2
y < −2x + 1
In 9–11, describe the shaded region with a system of inequalities.
9. 10. 11.
10-9B
x
y
x
y
x
y
x
y
x
y
x
y
1-1-2-4-5-6-7-8
1
-2
-3
-4
-5
-6
-7
-8
2
3
4
5
6
7
8
2 3 4 5 6 7 8
x
y
1-1-2-3-4-5-6-7-8
1
-1
-2
-3
-4
-6
-7
-8
2
3
4
5
6
7
8
2 4 5 6 7 8
x
y
1-1-2-3-4-5-6-7-8
1
-1
-2
-3
-4
-5
-6
-7
-8
2
3
4
5
6
7
8
2 3 4 5 6 7 8
x
y
SMP08ALG_NA_TR2_C10.indd 465 5/31/07 10:49:14 AM
Back to Lesson 10-9 Answer Page
466 Algebra
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raw
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Questions on SPUR ObjectivesSee pages 650–653 for objectives.
SKILLS Objective E
In 1 and 2, solve the system.
1. y = x 2 - 4
y = 3
2. y = x 2 - 5
y = 4x
3. True or false. (−3, 8) is a solution to the system y = x 2 - 1
y = 8
.
4. How many solutions does the system x 2 + y = 8
y = 2x
have?
REPRESENTATIONS Objective I
In 5 and 6, solve the system by graphing.
5. y = 2x + 2
y = x 2 + 2
6. y = x 2 - 6x + 9
y = 2x - 7
7. Randy graphed the system y = x 2 + 8x + 16
y = −x 2 - 8x -8
in
the standard window as shown at the right. Use
the graph to approximate the solutions
to the system.
10-10A Lesson Master
x
y
x
y
Back to Lesson 10-10 Answer Page