" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
Verified answer
[Barisan dan deret]Beda = (U8 - U5)/(8 - 5)
Beda = (13 - 40)/3
Beda = -27/3
Beda = -9
U5 = a + 4b
40 = a + 4(-9)
a = 40 + 36
a = 76
Maka...
Sn = n/2(2a + (n - 1)b)
S12 = 6(152 + 11 . (-9))
S12 = 6(152 - 99)
S12 = 318