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12.4.8: Chapter 8

  • Page ID
    119029
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    Be Prepared

    8.1

    28 28

    8.2

    x 5 x 5

    8.3

    yes

    8.4

    1 1

    8.5

    8 3 8 3

    8.6

    25 25

    8.7

    4 y 4 y

    8.8

    4 4

    8.9

    21 21

    8.10

    3 3

    8.11

    12 12

    8.12

    478 478

    Try It

    8.1

    no

    8.2

    no

    8.3

    x = −16

    8.4

    x = −20

    8.5

    n = −1

    8.6

    x = −4

    8.7

    p = 7 6 p = 7 6

    8.8

    q = 2 3 q = 2 3

    8.9

    b = 6.4

    8.10

    c = 14

    8.11

    y = 15

    8.12

    z = 2

    8.13

    p = 5

    8.14

    q = −16

    8.15

    h = −1

    8.16

    x = 1

    8.17

    x + 11 = 41; x = 30

    8.18

    y − 12 = 51; y = 63

    8.19

    4x − 3x = 14; x = 14

    8.20

    7a − 6a = −8; a = −8

    8.21

    a + 6 = 13; Athena weighs 7 pounds.

    8.22

    26 + h = 68; Henry has 42 books.

    8.23

    19,875 = s − 1025; the sticker price is $20,900.

    8.24

    7.75 = n − 3.25; the price at night is $11.00.

    8.25

    y = −16

    8.26

    z = −13

    8.27

    b = 144

    8.28

    c = 128

    8.29

    k = −8

    8.30

    g = −3

    8.31

    n = 35

    8.32

    y = 18

    8.33

    x = 2

    8.34

    n = −5

    8.35

    c = −3

    8.36

    x = 4 7 x = 4 7

    8.37

    n = −6

    8.38

    n = −5

    8.39

    x = −4

    8.40

    a = −8

    8.41

    y = 5

    8.42

    m = 9

    8.43

    n = 10

    8.44

    c = 1

    8.45

    p = −7

    8.46

    m = −3

    8.47

    j = 2

    8.48

    h = 1

    8.49

    x = −1

    8.50

    y = 4

    8.51

    q = 1

    8.52

    n = 1

    8.53

    a = −5

    8.54

    k = −6

    8.55

    x = 10

    8.56

    y = −3

    8.57

    x = −5

    8.58

    y = −5

    8.59

    x = 4

    8.60

    y = 1

    8.61

    y = −6

    8.62

    z = 8

    8.63

    a = 2

    8.64

    n = 2

    8.65

    j = 5 3 j = 5 3

    8.66

    k = 5 2 k = 5 2

    8.67

    p = −2

    8.68

    q = −8

    8.69

    u = 2

    8.70

    x = 4

    8.71

    n = 1

    8.72

    m = −1

    8.73

    x = 1 2 x = 1 2

    8.74

    y = 3

    8.75

    v = 40

    8.76

    u = −12

    8.77

    a = −2

    8.78

    c = −2

    8.79

    p = −4

    8.80

    q = 2

    8.81

    n = 2

    8.82

    m = −1

    8.83

    x = 20

    8.84

    x = 10

    8.85

    h = 12

    8.86

    k = −1

    8.87

    n = 9

    8.88

    d = 16

    Section 8.1 Exercises

    1.

    yes

    3.

    no

    5.

    x = 5

    7.

    b = 1 2 b = 1 2

    9.

    p = −11.7

    11.

    a = 10

    13.

    x = 7 3 x = 7 3

    15.

    y = 13.8

    17.

    x = −27

    19.

    q = 1 4 q = 1 4

    21.

    y = 27 20 y = 27 20

    23.

    m = 17

    25.

    x = 8

    27.

    n = −20

    29.

    y = 2

    31.

    w = −1.7

    33.

    x = −2

    35.

    m = −4

    37.

    k = 6

    39.

    c = −41

    41.

    y = 28

    43.

    x + (−5) = 33; x = 38

    45.

    y − 3 = −19; y = −16

    47.

    p + 8 = 52; p = 44

    49.

    5c − 4c = 60; c = 60

    51.

    f 1 3 = 1 12 ; f = 5 12 f 1 3 = 1 12 ; f = 5 12

    53.

    −9m + 10m = −25; m = −25

    55.

    Let p equal the number of pages read in the Psychology book. 41 + p = 54. Jeff read 13 pages in his Psychology book.

    57.

    Let d equal the daughter’s age. d = 12 − 5. Eva’s daughter’s age is 7 years old.

    59.

    21 pounds

    61.

    100.5 degrees

    63.

    $121.19

    65.

    d = 13 24 d = 13 24

    67.

    Answers will vary.

    Section 8.2 Exercises

    69.

    p = 9

    71.

    x = 3

    73.

    y = −6

    75.

    m = 7

    77.

    a = 15

    79.

    x = 0

    81.

    z = 28

    83.

    c = 36

    85.

    q = −48

    87.

    p = 80

    89.

    r = 25

    91.

    x = −32

    93.

    q = 5 2 q = 5 2

    95.

    y = −1

    97.

    m = −5

    99.

    t = 5 2 t = 5 2

    101.

    q = 24

    103.

    p = 56

    105.

    6 children

    107.

    $1.08

    109.

    42 yards

    111.

    Answer will vary.

    Section 8.3 Exercises

    113.

    x = 6

    115.

    y = 6

    117.

    m = −8

    119.

    b = −8

    121.

    x = −4

    123.

    q = −2

    125.

    k = −11

    127.

    x = 9

    129.

    b = −3

    131.

    z = 3

    133.

    x = 3 4 x = 3 4

    135.

    r = −2

    137.

    x = 19

    139.

    f = 7

    141.

    q = −5

    143.

    c = −4

    145.

    x = 2

    147.

    y = 4

    149.

    m = −6

    151.

    a = 7

    153.

    a = −40

    155.

    p = 15

    157.

    z = 3.46

    159.

    w = 60

    161.

    x = 23

    163.

    y = 9

    165.

    x = 6

    167.

    y = 3

    169.

    n = −2

    171.

    p = −1

    173.

    x = 5

    175.

    v = 1

    177.

    m = 0.25

    179.

    t = −9

    181.

    b = 2

    183.

    m = 6

    185.

    k = 3 2 k = 3 2

    187.

    r = 3

    189.

    y = −4

    191.

    n = 2

    193.

    x = 34

    195.

    s = 10

    197.

    x = 1 2 x = 1 2

    199.

    30 feet

    201.

    8 nickels

    203.

    Answers will vary.

    205.

    Answers will vary.

    207.

    Answers will vary.

    Section 8.4 Exercises

    209.

    x = −1

    211.

    y = −1

    213.

    a = 3 4 a = 3 4

    215.

    x = 4

    217.

    m = 20

    219.

    x = −3

    221.

    w = 9 4 w = 9 4

    223.

    x = 1

    225.

    b = 12

    227.

    x = 1

    229.

    p = −41

    231.

    x = 5 2 x = 5 2

    233.

    y = 10

    235.

    j = 2

    237.

    x = 18

    239.

    x = 18

    241.

    x = 20

    243.

    n = 9

    245.

    d = 8

    247.

    q = 11

    249.

    d = 18

    251.

    Answers will vary.

    253.

    Answers will vary.

    Review Exercises

    255.

    yes

    257.

    no

    259.

    12

    261.

    a = 4 3 a = 4 3

    263.

    u = 17

    265.

    c = 12 11 c = 12 11

    267.

    n = 44

    269.

    f = 10 3 f = 10 3

    271.

    y = 4

    273.

    n = −8

    275.

    −6 + m = 25; m = 31

    277.

    s = 11 − 3; 8 years old

    279.

    c − 46.25 = 9.75; $56.00

    281.

    x = 9

    283.

    p = 21

    285.

    n = 108

    287.

    x = 48

    289.

    m = 4

    291.

    x = 15

    293.

    r = 3

    295.

    p = 5

    297.

    x = −22

    299.

    y = −13

    301.

    k = −5

    303.

    x = 6

    305.

    u = −7

    307.

    x = −2

    309.

    s = −22

    311.

    y = 12

    313.

    r = 38

    315.

    y = 26

    317.

    n = 2

    319.

    a = 14 3 a = 14 3

    321.

    x = 5

    323.

    p = −20

    Practice Test

    325.
    1. yes
    2. no
    327.

    c = 16

    329.

    x = −5

    331.

    x = 9

    333.

    y = 4

    335.

    m = 6

    337.

    d = −32

    339.

    x = −2

    341.

    p = 2 3 p = 2 3

    343.

    2x − 4 = 16; x = 10


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