Matematika

Pertanyaan

tolong dijawab please no 3
tolong dijawab please no 3

1 Jawaban

  • (3x - 7) / 5 - (y + 5) / 3 = 3
    3(3x - 7) - 5(y + 5) = 3 (5 × 3)
    9x - 21 - 5y - 25 = 3 × 15
    9x - 5y = 45 + 46
    9x - 5y = 91 ... pers 1

    (x - 5) / 4 + (2y + 10) / 3 = 3
    3(x - 5) + 4(2y + 10) = 3 (4 × 3)
    3x - 15 + 8y + 40 = 3 × 12
    3x + 8y = 36 - 25
    3x + 8y = 11 ... pers 2

    9x - 5y = 91
    3x + 8y = 11 |×3

    9x - 5y = 91
    9x + 24y = 33
    ----------------------(-)
    - 29y = 58
    y = - 2

    3x + 8y = 11
    3x + 8(-2) = 11
    3x = 11 + 16
    3x = 27
    x = 9

    x = 9 dan y = - 2 (B)