29803813 หน วพะยการเรียนรู ที 3 ระบบสมการเชิงเส น

Embed Size (px)

DESCRIPTION

ะพ

Citation preview

  • 5/24/2018 29803813 3

    1/40

    101

    3

    4.2 : 3, 4 56.1 : 1 26.2 : 16.3 : 16.4 : 1 26.5 : 1

    1.

    2. 3.

    4.

    3.1 (3 )3.2 (6 )3.3 (6 )

    ?

  • 5/24/2018 29803813 3

    2/40

    102 .3

    .3

    +, , , ,

    1) 5 6 7 3 24

    2) 9 3 4 1 24

    3) 1 2 3 5 24

  • 5/24/2018 29803813 3

    3/40

    3 103

    .3

    33..11

    :

    1.

    2.

    / : 1. 2. 3. 4. 5. 6.

    : 1. 2. 3. 4. 5. 6.

    M T

    Series

  • 5/24/2018 29803813 3

    4/40

    104 .3

    .3

    10 x y

    x 1 2 3 4 5 6 7 8 9

    y 9 8

    (1, 9), (2, 8), .

    x y

    Y

    0 1 2 3 4 5 6 7 8 9 X

    1 5

    x + y = 10 x + y = 10

    x y

    9

    87

    6

    5

    4

    3

    2

    1

  • 5/24/2018 29803813 3

    5/40

    3 105

    .3

    Y

    0 1 2 3 4 5 6 7 8 9 X

    x + 3y = 2, 2x y = 4 3x + 2y = 6

    Ax + By + C = 0 (*)

    x, y A, B, C A 0 B 0(x, y) (*)

    Ax + By + C = 0

    x 3y = 6 (1)

    2x 6y = 8 (2)

    (1) (2)

    a, b, c, d, e f a, b c, d

    ax + by = e

    cx + dy = f

    x y

    a c x b d y

    9

    8

    7

    6

    5

    4

    3

    2

    1

  • 5/24/2018 29803813 3

    6/40

    106 .3

    .3

    (x, y) (x, y) x y

    1 x + y = 6 (1)

    2x y = 3 (2)

    x x

    y y

    x + y = 6 2x y = 3

  • 5/24/2018 29803813 3

    7/40

    3 107

    .3

    2 x + y = 2 (1)

    2x + 2y = 4 (2)

    x x

    y y

    x + y = 2 2x + 2y = 4

    5 ..

  • 5/24/2018 29803813 3

    8/40

    108 .3

    .3

    3 y x = 3 (1)

    y = x + 3 (2)

    x x

    y y

    y x = 3 y = x + 3

    (1)(2)(3)

  • 5/24/2018 29803813 3

    9/40

    3 109

    .3

    1. 1) x + 2y = 4, 2x + 3y = 7

    x x

    y y

    2) y + x = -2, 2y + 2x = -4

    x x

    y y

    3.1 :

  • 5/24/2018 29803813 3

    10/40

    110 .3

    .3

    3) x 3y = 6, 2x 6y = 8

    x x

    y y

    4) 2x + y = -3, 4x + 2y = -6

    x x

    y y

  • 5/24/2018 29803813 3

    11/40

    3 111

    .3

    5) 2y x = 6, 2y = x 4

    x x

    y y

    6) 2x 3y 14 = 0, 3x + 2y = 8

    x x

    y y

  • 5/24/2018 29803813 3

    12/40

    112 .3

    .3

    2. 1)

    2)

    6y + 4x = -12

    3y + 2x = -6

    2x + y = 3

    2x + y + 5 = 0

  • 5/24/2018 29803813 3

    13/40

    3 113

    .3

    3)

    4)

    x + 2y = 4

    2x - 3y = 1

    x + y = 0 x 3 = 0

  • 5/24/2018 29803813 3

    14/40

    114 .3

    .3

    5)

    6)

    x + 2y = 4y = x + 5

  • 5/24/2018 29803813 3

    15/40

    3 115

    .3

    33..22

    / : 1. 2. 3. 4. 5. 6.

    : 1. 2. 3. 4. 5. 6.

    : 1. 2.

    M T

    Series

  • 5/24/2018 29803813 3

    16/40

    116 .3

    .3

    1 2

    1) (

    )2) 1) 3) 2)4) 3) 1)

    1 x + y = 16 y x = 2 x + y = 16 (1)

    y x = 2 (2)

    (2) x y = 2 + x (3) y (3) (1)

    x + (2 + x) = 16

    2x + 2 = 16

    2x = 16 2 =

    2x

    2 =

    x =

  • 5/24/2018 29803813 3

    17/40

    3 117

    .3

    x = 7 (3) y = 7 + 2 = 9

    x y (1) (2) 7 + 9 = 16

    9 7 = 2 (7, 9)

    2 x y = 6 2x y = 4 x y = 6 (1)

    2x y = 4 (2)

    (1) y x = 6 + y (3) x (3) (2)

    2(6 + y) y = 4

    12 + 2y y = 4

    12 + y = 4

    y =

    y =

    y = -8 (3) x = 6 + =

    x y (1) (2) = 16

    = 4

  • 5/24/2018 29803813 3

    18/40

    118 .3

    .3

    1. x + y = 20 x y = 4 ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    2. x + y = 12 2x y = 3 ..

    ..

    ..

    ..

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    3.2 :

  • 5/24/2018 29803813 3

    19/40

    3 119

    .3

    3. 2x + y = 6 3x + 4y = 4

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    4. x + 2y = 1 x 2y = 5 ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

  • 5/24/2018 29803813 3

    20/40

    120 .3

    .3

    1) Ax + By = C A, B, C 2)

    ... 10 100 1,000,

    3) 4) 5)

    3 5x + 3y = 17 -5x + 2y = 3 5x + 3y = 17 (1)

    -5x + 2y = 3 (2)

    (1) + (2) (5x + 3y) + (-5x + 2y) = 17 + 3

    5y = 20

    =

    y = =

    =

    =

    =

    =

    x y (1) (2) =

    =

    (1) + (2) (1) (2) x

  • 5/24/2018 29803813 3

    21/40

    3 121

    .3

    4 3x + 3y = 15 2x + 6y = 22

    3x + 3y = 15 (1)

    2x + 6y = 22 (2)

    (1)2 6x + 6y = 30 (3)(3) (2)

    (6x + 6y) (2x + 6y) = 30 22

    =

    =

    =

    =

    =

    =

    =

    x y (1) (2)

    =

    =

    5 2x + 4y = 3 3x + 6y = 8 2x + 4y = 3 (1)

    3x + 6y = 8 (2)

    (1)3 6x + 12y = 9 (3)(2) 2 6x + 12y = 16 (4)(3) (4) (6x + 12y) (6x + 12y) = 30 22

    =

    = ..

    (1) 2 y

  • 5/24/2018 29803813 3

    22/40

    122 .3

    .3

    6 x 2y = -3 -3x + 6y = 9

    x 2y = -3 (1)

    -3x + 6y = 9 (2)

    (2) (-3) = (3)(3) (2) (1)(1) (2) (1) 2y = x + 3

    =

    7 -0.3x + 0.5y = -0.1 0.01x 0.4y = -0.8 -0.3x + 0.5y = -0.1 (1)

    0.01x 0.4y = -0.8 (2)

    (1)10 = (3)(2) x + 40y = -38 (4)

    (4) 3 = (5)(3) + (5) =

    =

    =

    =

    =

    =

    =

    =

    x y (1) (2) =

    =

  • 5/24/2018 29803813 3

    23/40

    3 123

    .3

    8 12

    x +2

    3y = 1 3

    4x

    1

    3y = 2

    12x + 2

    3y = 1 (1)

    3

    4x

    1

    3y = 2 (2)

    (1) = = (3)

    (2) = = (4)

    (3) + (4) =

    =

    =

    =

    =

    =

    =

    =

    =

    x y (1) (2)

    =

    =

    ... 2 3

    ... 4 3

  • 5/24/2018 29803813 3

    24/40

    124 .3

    .3

    1. x + 3y = 7 -x + 4y = 7 ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    2. x 2y = 6 -x + 3y = -4 ..

    ..

    ..

    ..

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    3.3 :

  • 5/24/2018 29803813 3

    25/40

    3 125

    .3

    3. x + 7y = 8 3x + 2y = 5

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    4. 3x y = 7 4x 3y 11 = 0 ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

  • 5/24/2018 29803813 3

    26/40

    126 .3

    .3

    5. x + 2y 1 = 0 2x + 4y = 5

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    6. 4x 3y = 12 x = 34 y + 3

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

  • 5/24/2018 29803813 3

    27/40

    3 127

    .3

    7. 0.2x + 0.3y = 0.1 0.03x 0.01y = 0.07

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    8. 35

    x + 23

    y = 14 34 x 13 y = 14

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

  • 5/24/2018 29803813 3

    28/40

    128 .3

    .3

    9 2x = 5y + 1 24 7x = 3y 2x = 5y + 1 (1)

    24 7x = 3y (2)

    (1) x = (3)

    x = (2) =

    =

    =

    =

    =

    y = (3) =

    =

    =

    x y (1) (2) =

    =

  • 5/24/2018 29803813 3

    29/40

    3 129

    .3

    1. 11x + 8y = -12 13x 6y = 83 ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    2. 2x + 3y = 1.6 3x 4y = 4.1 ..

    ..

    ..

    ..

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    3.4 :

  • 5/24/2018 29803813 3

    30/40

    130 .3

    .3

    3. x + 7y = 8 3x + 2y = 5

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    4. 2x 3y = -9 3(x 1) = 5(y 4) + 2 ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

  • 5/24/2018 29803813 3

    31/40

    3 131

    .3

    33..33

    / : 1. 2. 3. 4. 5. 6. :

    1. 2. 3. 4. 5. 6.

    : 1. 2.

    M T

    Series

  • 5/24/2018 29803813 3

    32/40

    132 .3

    .3

    5

    1

    2 345

    1 43 23

    x y 43

    1

    2(x + y) = 43 (1)

    23 3y 2x = 23 (2)

    (1) 2 = (3)

    (3) 2 = (4)(2) + (4) . =

    . =

    . =

    . =

    . =

    ??

  • 5/24/2018 29803813 3

    33/40

    3 133

    .3

    . =

    .

    .

    2 78

    24 x y

    78 = (1)

    24 = (2)

    = (3)

    . =

    . =

    . =

    . =

    . =

    . =

    . =

    . =

    ...

  • 5/24/2018 29803813 3

    34/40

    134 .3

    .3

    3 36

    4

    36

    2x + 2y = 36 (1)

    4 = (2)

    (1) 2 = (3)(2) + (3) . =

    . =

    (3) (2) . =

    . =

    .

    .

    4 4 5.50 6 20 %

    x 4x y 5.50y x + y 4x + 5.50y 6 20 %

  • 5/24/2018 29803813 3

    35/40

    3 135

    .3

    120 100

    6 1006

    = 5120 5 5(x + y) 4x + 5.50y = 5(x + y)

    4x + 5.50y = 5x + 5y

    . =

    . =

    . =

    . =

    . =

    .

    3 6 3 .1 : 2

    5 9,600 6% 8% 632

    x 6%

    y 8%9,600

    x + y = 9,600 (1)

    6% 6100

    x

    8% 8100 x

  • 5/24/2018 29803813 3

    36/40

    136 .3

    .3

    632 = 632 (2)

    (2)100 = (3)(1) 6x + 6y = 57,600 (4)(3) (4) . =

    . =

    (1)

    . =

    . =

    6% 8% .6% 8% .

    6%

    8%

  • 5/24/2018 29803813 3

    37/40

    3 137

    .3

    1. 16

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    2. 2 3 35 3 6 60

    ....

    ..

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    3.5 :

  • 5/24/2018 29803813 3

    38/40

    138 .3

    .3

    3. 628 6

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    4. 12 14

    15 20 %

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

  • 5/24/2018 29803813 3

    39/40

    3 139

    .3

    5. 880,000 132,600 14% 16%

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    6. 10 1 200 920

    ....

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

    ..

  • 5/24/2018 29803813 3

    40/40

    140 .3

    .3