Matematika

Pertanyaan

tolong dijawab no 37 & 38 bsk di kmpl. Dgn jalannya ya trims
tolong dijawab no 37 & 38 bsk di kmpl. Dgn jalannya ya trims

1 Jawaban

  • MAPEL = MATEMATIKA
    KELAS = 9
    BAB = BARISAN & DERET

    ----------- Barisan Aritmatika --------

    37.)
    bentuk barisan :
    y, ( 2y + 1 ), 53, ....

    U1 = a = y
    U2 = ( 2y + 1 )
    U3 = 53

    beda :
    = U2 - U1
    = ( 2y + 1 ) - y
    = y + 1

    U3 = 53
    ➡ a + 2b = 53
    ➡ y + 2( y + 1 ) = 53
    ➡ y + 2y + 2 = 53
    ➡ 3y = 53 - 2
    ➡ 3y = 51
    ➡ y = 51/3
    ➡ y = 17

    jadi, U1 = y = 17

    38.)
    bentuk barisan :
    ( m + 1 ), 2m, 41, .....

    U1 = a = ( m + 1 )
    U2 = 2m
    U3 = 41

    beda :
    = U2 - U1
    = 2m - ( m + 1 )
    = m - 1

    U3 = 41
    ➡ a + 2b = 41
    ➡ ( m + 1 ) + 2( m - 1 ) = 41
    ➡ m + 1 + 2m - 2 = 41
    ➡ 3m - 1 = 41
    ➡ 3m = 41 + 1
    ➡ 3m = 42
    ➡ m = 42/3
    ➡ m = 14

    beda :
    = m - 1
    = 14 - 1
    = 13

    jadi, bedanya = 13
    semoga membantu