Tentukan suku ke-12 dari barisan aritmatika berikut! 2, 5, 8, 11, ... 35, 31, 27, 23, ... a. b. Jawab: devel
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Jawab:
a. 35
b. -9
Penjelasan dengan langkah-langkah:
a. 2, 5, 8, 11
b = u2-u1 = 5 - 2 = 3
un = a + (n-1)b
u12 = 2 + (12-1).3
u12 = 2 + 11.3
u12 = 2 + 33
u12 = 35
b. 35, 31, 27, 23
b = u2-u1 = 31 - 35 = -4
un = a + (n-1)b
u12 = 35 + (12-1).-4
u12 = 35 + 11.-4
u12 = 35 + (-44)
u12 = 35 -44
u12 = -9
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