Question

sabe se que numa p.a de 12 termos,a1=-8 ea12=36 calcule a razao dessa p.a

Answer 1

$a_{12}=a_1+11r\\ \\ 36=-8+11r\\ \\ 11r=44\\ \\r=\frac{44}{11}\\ \\ \boxed{r=4}$