Matematika

Pertanyaan

Nilai x,y dan z dari sistem persamaan berikut...
x + 2y - z = 2
-x + y + 3z = 10
-4x + 3y + z = 5
Adalah..

1 Jawaban

  • x + 2y - z = 2
    - x + y + 3z = 10
    - 4x + 3y + z = 5

    x + 2y - z = 2
    - z = 2 - x - 2y
    z = x + 2y - 2

    - x + y + 3z = 10
    - x + y + 3(x + 2y - 2) = 10
    - x + y + 3x + 6y - 6 = 10
    2x + 7y = 10 + 6
    2x + 7y = 16

    - 4x + 3y + z = 5
    - 4x + 3y + x + 2y - 2 = 5
    - 3x + 5y = 5 + 2
    - 3x + 5y = 7

    2x + 7y = 16|× 5
    - 3x + 5y = 7|× 7

    10x + 35y = 80
    - 21x + 35y = 49
    ____________—
    31x = 31
    x = 1

    2x + 7y = 16
    2 + 7y = 16
    7y = 16 - 2
    7y = 14
    y = 2

    z = x + 2y - 2
    z = 1 + 4 - 2
    z = 3

    x = 1
    y = 2
    z = 3

    Maaf Kalau Salah

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