Question

Tolong jawab pakai cara yang lengkap

Answer 1

U6 = a +5b
u9 = a +8b
u12=a +11b
u15= a + 14b
--------------- +
4a + 38b = 20

s20 = 20/2 ( a + u20)
       = 10 ( a + a +19b)
     = 10 ( 2a + 19b)
     = 5 ( 4a + 38b)
    = 5 (2)
   = 100  ... C

Answer 2

u6 = a +5b
u9 = a +8b
u12=a +11b
u15= a + 14b
--------------- +
4a + 38b = 20 bagi 2
2a + 19b = 10


S20 = 20/2 ( a + U20)
       = 10 ( a + a +19b)
      = 10 ( 2a + 19b)
      =  10(10)
      = 100 

jawaban C