Matematika

Pertanyaan

Nilai mutlak

|2x+1|-2=1

|x+7|=|3-x|

|3x-1|=|5+x|

1 Jawaban

  • Mapel : Matematika
    Kelas : X SMA
    Materi : Persamaan Nilai Mutlak

    Pembahsan :
    |2x + 1| - 2 = 1
    |2x + 1| = 3

    2x + 1 = 3
    2x = 2
    x = 1

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

    Hp : {-2 , 1}

    ————————————————
    |x + 7| = |3 - x|
    (x + 7)² = (3 - x)²
    (x + 7)² - (3 - x)² = 0
    (x + 7 + 3 - x)(x + 7 - 3 + x) = 0
    10(2x + 4) = 0
    20x + 40 = 0
    20x = -40
    x = -2

    Hp : {-2}

    ————————————————
    |3x - 1| = |5 + x|
    (3x - 1)² = (5 + x)²
    (3x - 1)² - (5 + x)² = 0
    (3x - 1 + 5 + x)(3x - 1 - 5 - x) = 0
    (4x + 4)(2x - 6) = 0
    x = -1
    x = 3

    Hp : {-1 , 3}

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