Respostas

2013-10-29T13:44:32-02:00
An= A1 + (n-1)R
A10 = -2 + (10-1)5
A10 = -2 + 45
A10 = 43 

Sn= (A1+AN).n/2
S10 = (-2 + 43).10/2
S10= 41*5
S10 = 205