Question

Calcule a soma dos termos da P.A (1, 4, 7, ..., 52)

Answer 1

52=1+(n-1).3
52=1+3n-3
3n -2 = 52
3n=54
n= 54/3
n = 18

s= (1+52).18/2
s = 53.18/2
s = 954/2
s = 477

bons estudos!