Question

Determine a P A cujo sexto termo vale -4 e cujo nono termo vale 11

Answer 1

$\left \{ {{ a_{1} + 5r=-4} \atop { a_{1} + 8r =11}} \right. \\ \\ 3r = 15 \\ r = 5 \\ \\ a_{1} + 5r=-4 \\ a_{1} + 25 =-4 \\ a_{1} = -29$

{-29, -24,-19, -14, -9, -4, 1, 6, 11}