Question

calcule a soma dos multiplos de 8 compreendidos entre 14 e 701

Answer 1

a₁ = 16

an= 696

r =8

696 = 16 + (n - 1) . 8 ------ 696 - 16 = (n - 1) . 8 ----- 680 = (n - 1) . 8

680/8 = n - 1 -------  n - 1 = 85 ---- n = 85 + 1 ----- n = 86


S₈₆ = [(16 + 696) . 86]/2 ------ S₈₆ = (712) . 43 ------- S₈₆ = 30616