Matematika

Pertanyaan

Himpunan penyelesaian dari 5/|x-3|>(x+1) adalah....

1 Jawaban

  • 5/|x - 3| > x + 1
    5/|x - 3| - (x + 1) > 0

    1) x ≥ 3 => |x - 3| = x - 3
    5/(x - 3) - (x + 1) > 0
    (5 - (x + 1)(x - 3))/(x - 3) > 0
    (5 - (x^2 - 2x - 3))/(x - 3) > 0
    (-x^2 + 2x + 8)/(x - 3) > 0
    -(x^2 - 2x - 8)/(x - 3) > 0
    -(x - 4)(x + 2)/(x - 3) > 0
    x = 4 atau x = -2 atau x = 3
    ++++ (-2) ---- (3) +++ (4) ---- ==> karena syarat x ≥ 3 maka
    HP = {3 < x < 4}

    2) x < 3 => |x - 3| = 3 - x
    5/(3 - x) - (x + 1) > 0
    (5 - (x + 1)(3 - x))/(3 - x) > 0
    (5 - (3x - x^2 + 3 - x)) / (3 - x) > 0
    (x^2 - 2x + 2)/(3 - x) > 0
    (definit positif)/(3 - x) > 0
    3 - x > 0
    -x > -3
    x < 3 ===> sesuai syarat : x < 3

    {3 < x < 4} U {x < 3}
    x < 3 atau 3 < x < 4

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