Question

Qual a razao da P.A. em que $a_{2}$ = -7 e $a_{8}$ = 17

Answer 1

$a_8=a_1+7R\\ \\ a_2=a_1+R\\ \\ a_8-a_2=6R\\ \\ 6R=17-(-7)\\ \\ 6R=24\\ \\ \boxed{R=4}$