Question

QUAL É O OITAVO TERMO DA P.A ( 1 3_2, 2...)

Answer 1

$a_n=a_8=? \\ a_1= \frac{13}{2} \\ n=8 \\ \\ r=2- \frac{13}{2} = \frac{4-13}{2} =- \frac{9}{2} \\ \\ termo~~geral \\ \\ a_n=a_1+(n-1)r \\ \\ a_8= \frac{13}{2} +(8-1)(- \frac{9}{2} \\ \\ a_8= \frac{13}{2} +(7)(- \frac{9}{2} ) \\ \\ a_8= \frac{13}{2} - \frac{63}{2} \\ \\ a_8=- \frac{50}{2} \\ \\ a_8=-25$