Question

Calcule a soma dos 32 primeiros termos da P.A. (-26, -15, -4 ).

Answer 1

An = ?
Sn= ?
A1= -26
r= 11
n=32

An= -26 +(32-1) * 11
An= -26 + 341
An= 315

sn= (315+(-26)) * 32
        ---------------------
                 2
Sn= 289 * 32
       -------------
              2
Sn= 9,248/2
Sn=4,624