Matematika

Pertanyaan

Diketahui:
3x + y = -2
-2x + 3y = 5
Nilai x - y adalah...
A. -2
B. -1
C. 0
D. 1

2 Jawaban

  • 3x + y = -2 | ×3 |
    -2x + 3y = 5 | ×1 |
    -------------------------
    9x + 3y = -6
    -2x + 3y = 5
    ------------------ -
    11x = -11
    x = -1

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

    Maka,
    x - y
    = -1 - 1
    = -2
    Jawaban : A
  • 3x + y = -2 (× 3)
    -2x + 3y = 5 (× 1)

    9x + 3y = -6
    -2x + 3y = 5
    ------------------ -
    11x = -11
    x = -11/11
    x = -1

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

    x - y = -1 - 1 = -2 (A)

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