Diketahui suku ke-9 & suku ke-13 suatu barisan aritmetika masing" 93 & 73. Jumlah 24 suku pertama adalah.... a)216. b)432. c)1.812. d)3.624 ...Beserta caranya! -Tolong y butuh cepat!
Dzaky111
U13 = a + 12b = 73 U9 = a + 8b = 93 4b = -20 b = -5 a + 8b = 93 a + 8(-5) = 93 a = 93 + 40 = 133 Sn = n/2(2a +(n-1)b) S24 = 12(266 + 23(-5)) = 12(266 -115) = 12 x 151 = 1812
U9 = a + 8b = 93
4b = -20
b = -5
a + 8b = 93
a + 8(-5) = 93
a = 93 + 40
= 133
Sn = n/2(2a +(n-1)b)
S24 = 12(266 + 23(-5))
= 12(266 -115)
= 12 x 151
= 1812