Matematika

Pertanyaan

tolong bantu jawab soal nomor 3 ya, kak

thanks before^^
tolong bantu jawab soal nomor 3 ya, kak thanks before^^

2 Jawaban

  • a)
    [tex] (x+2)^{x+4} = (x+2)^{ x^{2} +3x+1} [/tex]

    => x + 4 = x² + 3x + 1
         x² + 3x + 1 - x - 4 = 0
         x² + 2x - 3 = 0
         (x + 3) (x - 1) = 0
         x1 = -3;  x2 = 1

    b). x + 2 = 1
         x3 = 1 - 2 
              = -1

    Jadi himpunan penyelesaiannya adalah {-3, -1, 1}  ⇒ jawaban D
  • (x + 2)^(x + 4) = (x + 2)^(x^2 + 3x + 1)

    1) x + 2 = 1
    => x = 1 - 2
    => x = -1

    2) x + 2 = 0 jika (x + 4) > 0 dan (x^2 + 3x + 1) > 0
    => x = 0 - 2
    => x = -2
    (x + 4) = (-2 + 4) = 2 > 0
    (x^2 + 3x + 1) = (-2)^2 + 3(-2) + 1 = 4 - 6 + 1 = -1 => 0^-1 = 1/0^1 = 1/0 = ?
    karena (x^2 + 3x + 1) < 0 maka
    x = -2 tidak memenuhi

    3) x + 2 = -1 jika (x + 4) dan (x^2 + 3x + 1) sama2 ganjil atau sama2 genap
    => x = -1 - 2
    => x = -3
    (x + 4) = (-3 + 4) = 1 => ganjil
    (x^2 + 3x + 1) = (-3)^2 + 3(-3) + 1 = 9 - 9 + 1 = 1 => ganjil
    Jadi x = -3 memenuhi

    4) (x + 4) = (x^2 + 3x + 1)
    => 0 = x^2 + 2x - 3
    => (x + 3)(x - 1) = 0
    => x = -3 atau x = 1

    HP = {-3, -1, 1}