Question

A PA (127, 121, 115,⋯, −47) possui quantos termos?

Answer 1

Resposta:

$\textsf{Leia abaixo}$

Explicação passo a passo:

$\mathsf{a_n = a_1 + (n -1)r}$

$\mathsf{-47 = 127 + (n -1)(-6)}$

$\mathsf{-47 = 127 - 6n + 6}$

$\mathsf{-47 = 133- 6n}$

$\mathsf{6n = 133 + 47}$

$\mathsf{6n = 180}$

$\boxed{\boxed{\mathsf{n = 30}}}$