Question

dada o P.A (5,2,-1...)determine
a)o 31 termo
b)o termo geral

Answer 1

b)
$a_n=a_1+(n-1)r \\ \\ a_n=5-3(n-1) \\ \\ a_n=5-3n+3 \\ \\ \boxed{a_n=8-3n}$

a)
$\boxed{a_{31}=8-3.31=-85}$