Matematika

Pertanyaan

kuadrat dua variabel X²-3xy-2y²-2=0.dan x-y-2=0

2 Jawaban

  • Linear-Kuadrat Dua Variabel

    x² - 3xy - 2y² - 2 = 0

    x - y - 2 = 0

    Dari pers.linear :
    x = y + 2

    Substitusi

    (y + 2)² - 3(y + 2)y - 2y² - 2 = 0
    (y² + 4y + 4) - 3(y² + 2y) - 2y² - 2 = 0
    ( - y² + 4y + 2 - 3y² - 6y ) = 0
    -4y² - 2y + 2 = 0
    bagi dgn -2

    2y² + y - 1 = 0
    2y² + 2y - y - 1 = 0
    2y(y + 1) - 1(y + 1) = 0
    (2y - 1)(y + 1) = 0
    y = 1/2 v y = -1

    utk y = 1/2
    x = y + 2
    x = 1/2 +2
    x= 5/2

    utk y = -1
    x = -1+2
    x = 1

    Hp
    = { (5/2 , 1/2) , (1 , -1) }
  • System Equation.

    x - y - 2 = 0
    x - y = 2 → x = y + 2

    Substitute x to x² - 3xy - 2y² - 2 = 0
    (y + 2)² - 3(y + 2)y - 2y² - 2 = 0
    y² + 4y + 4 - 3y² - 6y - 2y² - 2 = 0
    -4y² - 2y + 2 = 0
    2y² + y - 1 = 0
    (2y² - y) + (2y - 1) = 0
    y(2y - 1) + (2y - 1) = 0
    (2y - 1)(y + 1) = 0
    y = 1/2 or y = -1

    For y = 1/2, x = 1/2 + 2 = 3/2
    For y = -1, x = -1 + 2 = 1
    HP = {(3/2, 1/2), (1, -1)}
    Gambar lampiran jawaban Anonyme

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