Matematika

Pertanyaan

1.Tentukan U10 dari deret berikut :
a.4,12,20
b.12,8,4
c.1,3,9,27
d.3,6,12,24

*Dikasih caranya*

1 Jawaban

  • a)
    4,12,20,...
    a = 4
    b = 12 - 4 = 8
    Un = a + (n - 1)b
    U10 = 4 + 9(8) = 72

    b) 12,8,4,...
    a = 12
    b = 8 - 12 = -4
    U10 = 12 + 9(-4) = -24

    c) 1,3,9,27,...
    a = 1
    r = 3/1 = 3
    Un = ar^(n-1)
    U10 = 1.(3)^9 = 3^9

    d) 3,6,12,24,...
    a = 3
    r = 6/3 = 2
    U10 = 3.2^9 = 1536

Pertanyaan Lainnya