Matematika

Pertanyaan

Tolong di bantuin ya no 9 sampai 15 sekali gus jalannya


#MB
Tolong di bantuin ya no 9 sampai 15 sekali gus jalannya #MB

1 Jawaban

  • 10.
    PS² = RS x SQ
           = RS x (QR - RS)
           = 9 x (34 - 9)
           = 9 x 25
           = 225
    PS = √225
    PS = 15 cm

    Luas segitiga = 1/2 x QR x PS
    L = 1/2 x 34 x 15
    L = 17 x 15
    L = 255 cm² (D)

    11.
    RN : RQ = 2 : 5
    maka
    RN : NQ = 2 : 3

    MN = (PQ x RN + SR x NQ) / RQ
    MN = (25 x 2 + 10 x 3) / 5
    MN = (50 + 30) / 5
    MN = 80 / 5
    MN = 16 cm (B)

    12.
    DC : CB = 2 : 3
    maka
    DB = 2 + 3 = 5

    FC = (AB x DC + ED x BC)/ DB
    12 = (AB x 2 + 8 x 3) / 5
    12 x 5 = 2AB + 24
    60 = 2AB + 24
    2AB = 60 - 24
    2AB = 36
    AB = 18 cm

    AB - DE = 18 cm - 8 cm = 10 cm (C)

    13.
    t / 160 = 3,2 / 4
    t / 160 = 4/5
    t = 4/5 x 160
    t = 128 cm (B)

    14.
    ukuran foto
    alas = 32 cm
    tinggi = 40 cm

    ukuran bingkai
    lebar = 32 + 4 + 4 = 32 + 8 = 40 cm
    panjang = p

    p / 40 = 40 / 32
    p / 40 = 5/4
    p = 5/4 x 40
    p = 50 cm

    misal lebar bagian bawah bingkai = L
    2L = panjang bingkai - tinggi foto
    2L = 50 - 40
    2L = 10
    L = 5 cm (B)

    15.
    BC = AB = 10 cm
    AC² = AB² + BC²
    AC² = 10² + 10²
    AC² = 100 + 100
    AC² = 200
    AC = √200
    AC = 10√2

    BD / AD = BC / AC
    BD / (10 - BD) = 10 / 10√2
    10√2 BD = 10(10 - BD)
    10√2 BD = 100 - 10 BD
    10√2 BD + 10 BD = 100
    BD(10√2 + 10) = 100
    BD = 100 / (10√2 + 10)
    BD = 100 / [10(√2 + 1)]
    BD = 10 / (√2 + 1)
    BD = 10(√2 - 1) / (2 - 1)
    BD = (10√2 - 10) cm (B)