Question

Numa P.A de 12 termos, a1 = -2 e a12 =36 calcule a razão dessa P.A

Answer 1

termo geral:
$an=a1+(n-1)d$
$a12=a1+(12-1)d$
$36=-2+11d$
$11d=38$
$d= \frac{38}{11}$

Resposta: razao=38/11