Quiz! #DilarangJawabAsal-Asalan #DilarangSpam

Un= a+(n-1)b
U11=a+(11-1)b
21=a+10b

U21= a+(21-1)b
U21=a+20b
U21=(a+10b)+10b
U21=21+10b

Sn= n/2(a+Un)
S21=21/2(a+21+10b)
S21=21/2(21+21)
S21=21*21
S21=441