Matematika

Pertanyaan

tentukan himpunan penyelesaian dari:
1. 2 | x | + 1 = 5
2. | 5x + 3 | = | 2x |
3. 4 | x-2 | = 8
4. 2 - | x-2 | = x

Mohon Bantuannya

1 Jawaban

  • Mapel : Matematika
    Kelas : X SMA
    Bab : Mutlak

    Pembahasan :
    2|x| + 1 = 5
    2|x| = 4
    |x| = 2

    Maka x = -2 atau x = 2

    Hp : {-2 , 2}

    ————————————————
    |5x + 3| = |2x|
    (5x + 3)² = (2x)²
    (5x + 3)² - (2x)² = 0
    (3x + 3)(7x + 3) = 0
    x = -3/7
    x = -1

    Hp : {-3/7 , -1}

    ————————————————
    4|x - 2| = 8
    |x - 2| = 2
    (x - 2)² - 2² = 0
    x(x - 4) = 0
    x = 0
    x = 4

    Hp : {0 , 4}

    ————————————————
    2 - |x - 2| = x
    |x - 2| = 2 - x
    (x - 2)² = (2 - x)²
    (x - 2)² - (2 - x)² = 0
    2x - 4 = 0
    2x = 4
    x = 2

    Hp : {2}

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