5+19+13+17 s=37deret aritmatika

Sn = ½ . n (a+Un)
S37 = ½ 37 (5+509)
= 18,5 . 514
= 9509

Un = a + (n-1) b
= 5 + (37-1) 14
= 5 + 36 . 14
= 5+504
= 509

semoga membantu :))