Respostas

  • Usuário do Brainly
2014-04-02T21:43:36-03:00
Sn= (a1+an).n/2---> an= a1+(n-1).r---> an= 200+(110-1).-2-----> an= -18
Logo, 
sn= 200+(-18).110/2---> sn= 200-990
sn= -790.
bjs