Question

Se considera progresia aritmetica ( an ) n≥1 in care a1 = 1 si r = 3 . Sa se calculeze a7 . MULTUMESC .

Answer 1

a1=1
r=3
a7=?
$a_{7}=a_{1}+6r\ \textless \ =\ \textgreater \ a_{7}=1+6*3=1+18=19=\ \textgreater \ a_{7}=19$