Matematika

Pertanyaan

Jika selisih akar akar x^+2mx+(19+m)=0 adalah 2, maka nilai m^-m+3 = ...

2 Jawaban

  • Jawab :

    Jawab bareng Kakakku To9ha :D

    x² + 2mx + (19 + m) = 0
    a = 1
    b = 2m
    c = 19 + m

    D = b² - 4ac = 4m² - 4(19 + m)

    x1 - x2 = 2
    √D /a = 2
    Kuadratkan kedua ruas
    D/a² = 2²
    4m² - 4(19 + m) = 4
    4m² - 4m - 76 - 4 = 0
    m² - m - 20 = 0
    m² - m = 20

    Maka,
    m² - m + 3
    = 20 + 3
    = 23 ✔


  • jawab

    x² + 2m x + (19+m) = 0
    a= 1
    b = 2m
    c = 19 +m

    x1 + x2 = -b/a= 2m
    x1x2 = c/a = 19+m

    x1- x2 = 2
    (x1 - x2)² = 2²
    x1² + x2² - 2x1 x2 = 4
    (x1 + x2)² - 4 x1x2 = 4
    (2m)² - 4(19+m) = 4
    4m² - 76 - 4m  - 4= 0
    4m² - 4m - 80 =0
    m² - m - 20 = 0
    (m - 5)(m +4)= 0
    m = 5  atau m = - 4

    nilai  P= m² - m + 3 
    m= 5 → P = 25-5+ 3 = 23
    m= - 4 → P = 16-(-4)+3 = 23

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