Answer Key

Chapter   3  –  Equations   of   Lines Answer   Key

3.1

OneStep   Equations   and   Inverse   Operations

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

x = 18 x = 4.3 x = .743 x = − 1 65 5 x = 1 24

q = 0 z = 1.9001 r = − 53 t = − 61 y = − 1 41

CK12   Algebra   I  Concepts

1

Chapter   3  –  Equations   of   Lines Answer   Key

3.2

OneStep   Equations   Transformed   by Multiplication/Division

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

x = 3 x =

1 4

x = 1 53 x = 1100 x = − 15 s =

1 7

a=

5 7

f = 1 r = b=

1 16 2 3



CK12   Algebra   I  Concepts

2

Chapter   3  –  Equations   of   Lines Answer   Key

3.3

Applications   of   OneStep   Equations

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

n + 10 = 25 w= n w

10 8

:   w =

5 4

= r    : 15 5 = r    : r = 12 4

3(8.50   +  1.25)   =  u 3(8.50+1.25) 12

=c

2(8.50 + 1.25) = w 10   dozen   or   120   cookies 2.5   cups   per   batch 3   eggs   per   batch 3   more   eggs 4   batches,   8  dozen   or   96   cookies.

CK12   Algebra   I  Concepts

3

Chapter   3  –  Equations   of   Lines Answer   Key

3.4

TwoStep   Equations   and   Properties   of   Equality

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

x   =  .75 x   =  2.75 8 x = 1 15 or 1.53 1 x = − 3 18

y = − 110 q = 3 q = 8 53 t = 3 p = 6 54 y=

1 2

y = − 4

CK12   Algebra   I  Concepts

4

Chapter   3  –  Equations   of   Lines Answer   Key

3.5

MultiStep   Equations   with   Like   Terms

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

x = 20 a = − 2 y = 4 x = 2 x = 1 21 s = 1 31 y =

1 6

x = 3.81… x = 24 x = 1

CK12   Algebra   I  Concepts

5

Chapter   3  –  Equations   of   Lines Answer   Key

3.6

Solving   RealWorld   Problems   with   TwoStep Equations

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

2.35 + .75x = 10,      x = 10.2 miles 150 + 3x = 300,      x = 50 guests 3   trips 4   trips 7   trips 6   trips The   variable   (c)   represents   the   number   of   children:   c  +  5c 33 66 70

CK12   Algebra   I  Concepts

6

Chapter   3  –  Equations   of   Lines Answer   Key

3.7

MultiStep   Equations

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

x = 9 x = − 11 w = − 22.5 w = 19 x = 3.5 t = 4.5833… d = − 41 a=

2 21

i = 1 52 v = 4 81 g   =  20 m = − 4 32     k=

2 5

z = 7 21 r = 1 21 z = 2 71

CK12   Algebra   I  Concepts

7

Chapter   3  –  Equations   of   Lines Answer   Key

3.8

Solving   RealWorld   Problems   Using   MultiStep Equations

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

s = 8 52 5 k = 1 16 5 x = 1 14

y = 2 r = 8 52 p = −

16 87

200 + 40x = 2(250),   40x = 300,   x = 28. 5   bags   per   load. 12v = 1. 2a(3x   +4),   x  =  2 3/5 x × 1.10 = (2/5 x + 500).80,   x = 1176.47 H e drove 70 miles.

CK12   Algebra   I  Concepts

8

Chapter   3  –  Equations   of   Lines Answer   Key

3.9

Equations   with   Variables   on   Both   Sides

Answers 1. 2.

x = 9 x = − 22 21

3.

x = 3 21

4.

a=

7 12

5.

t = 3 97

6.

v=

141 61 80 or 1 80

7.

y = −

82 29 or

24

− 2 29

8.

z=

32 87

9.

q= −

232 15 or

7

− 15 15

10.

x =− 3

11.

  p = 23

CK12   Algebra   I  Concepts

9

Chapter   3  –  Equations   of   Lines Answer   Key 12.

  a.  x = 9   b.  42   c .  (11 x 3) + x = 42

13.

14.

15. 16.

a.  7   b. − 1   c .  no   d.  check students work to assure their answer works . 5x + 6 = 9(x − 4) − 2 a.    C D’s are on sale f or $7.00 b.    I would have to borrow $38.00. 6.5Ω a.   The   unknown   resistor   is   25 Ω b.   The   unknown   resistor   is   30 Ω c.   Each   unknown   resistor   is   9.5 Ω d.   The   unknown   resistor   is   1.21 Ω

CK12   Algebra   I  Concepts

10

Chapter   3  –  Equations   of   Lines Answer   Key

3.10

Ratios

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

50 : 1 6 : 7 10 : 3 5 : 7 4.5 hotdogs per minute 20 lbs per square inch 4 students per computer 30 students per teacher 3 meters per f loor 1.2 minutes per appointment

CK12   Algebra   I  Concepts

11

Chapter   3  –  Equations   of   Lines Answer   Key

3.11

Proportions

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

x = 2.31 x = 20.16 x = 3.47 x = 500 x = 7425 x = .0670012 x = .4225 x = 19.19 x = 4 61 x = 2.07

CK12   Algebra   I  Concepts

12

Chapter   3  –  Equations   of   Lines Answer   Key

3.12

Scale   and   Indirect   Measurement   Applications

Answers 1. They   would   earn   $2,270,   if   they   served   250   people. 2. Mt   Yukon   is   5,960   feet   (Mt   Bleck   is   4800   feet.    Mt.   Elbert   is   4400   feet    Ben   Nevis   is   1,340   feet) 3. 13/15   students   who   own   a  cell   phone   own   one   that   is   more   than   one   year   old. 4. 12   kilometers 5. 6   kilometers 6. 4   kilometers 7.

7.10.:   MISSING   ANSWER

CK12   Algebra   I  Concepts

13

Chapter   3  –  Equations   of   Lines Answer   Key

3.13

Conversion   of   Decimals,   Fractions,   and   Percent

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20.

1.1% .1% 91% 175% 2000% .15 .0008 2.22 .035 3.419 16.66% 20.83% 85.71% 157.14% 13.4% 11 100

65 100

=

13 20

16 100

=

4 25

125 1000

=

1 8



875 1000

=

7 8

CK12   Algebra   I  Concepts

14

Chapter   3  –  Equations   of   Lines Answer   Key

3.14

Percent   Equations

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

27 5.13 33.233 1.15 0.0365 167.5 0.345y 0 .1702y 280(0.01)x 0.332(0.01a) 3x(0.01y)

CK12   Algebra   I  Concepts

15

Chapter   3  –  Equations   of   Lines Answer   Key

3.15

Percent   of   Change

Answers 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

$80.50 $84.00 $87.50 1.282 0.071 $10.64 per hour P re − sale price of $300.00 20% of f No,   the   $40   would   not   be   the   same   percentage   if   the   initial   price   were   different.   S tore A

CK12   Algebra   I  Concepts

16

Recommend Documents