Question

qual o sexto termo de uma P.A de razão iqual a 1/2 e primeiro termo iqual a 4?

Answer 1

$a_n=a_6=? \\ a_1=4 \\ n=6 \\ r= \frac{1}{2} \\ \\ a_n=a_1+(n-1)r \\ \\ a_6=4+(6-1)( \frac{1}{2} ) \\ \\ a_6=4+5( \frac{1}{2} ) \\ \\ a_6=4+ \frac{5}{2} \\ \\ a_6= \frac{8+5}{2} \\ \\ a_6= \frac{13}{2}$