Question

1) An=785 ; A1=5 ; R=5 ; N=? me ajudem

Answer 1

An= a1 + (n-1).r
785 = 5 + (n-1).5
785 -5 = (n-1).5
780 = (n-1).5
n-1 = 780/5
n-1 = 156
n= 157

Answer 2

Bom Dia!

Dados:

a1 → 5

an → 785

r → a2-a1 → 10-5 = 5

n → ?

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An=a1+(n-1)·r

785=5+(n-1)·5

785=5+5n-5

785-5n=5-5

-5n=0-785

-5n=-785 (-1)

5n=785

n=785/5

n=157

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Att;Guilherme Lima