" Life is not a problem to be solved but a reality to be experienced! "
© Copyright 2013 - 2024 KUDO.TIPS - All rights reserved.
Maka suku pertamanya a=6
Sn = n/2(2a+(n-1)b)
S20 = 20/2(2×6+(20-1)3) = 10(12+(19)3) = 10(12+57) = 10(68) = 680 ..
Semoga bermanfaat ..