Matematika

Pertanyaan

Bantu jawab pake cara
Bantu jawab pake cara

2 Jawaban

  • 2x² + 6x - 1 = 0
    a = 2
    b = 6
    c = -1

    x1 + x2
    = -b/a
    = -6/2
    = -3

    x1.x2
    = c/a
    = -1/2

    Nilai x1² + x2²
    = (x1 + x2)² - 2x1.x2
    = -3² - 2 (-1/2)
    = 9 + 1
    = 10
  • Mapel : Matematika
    Kelas : X SMA
    Bab : Persamaan Kuadrat

    Pembahasan :
    2x² + 6x - 1 = 0

    Berdasarkan Teorema Vietta
    X1 + X2 = -b/a
    X1 + X2 = -6/2
    X1 + X2 = -3

    X1 . X2 = c/a
    X1 . X2 = -1/2

    Maka...
    X1² + X2²
    = (X1 + X2)² - 2(X1 . X2)
    = (-3)² - 2(-1/2)
    = 9 + 1
    = 10