Question

Determine o número de termo da P.A. (-6,-9,-12,...,-66)

Answer 1

(- 6, - 9, - 12, ...,  - 66)

a₁ = - 6

r = - 9 - ( -6) ---- r = - 9 + 6 --- r = - 3

- 66 =  - 6 + (n - 1) . (-3) --- - 66 + 6 = (n - 1) . (-3) ---- - 60 = (n - 1) . (-3)

(n - 1) = - 60/ (-3) ----- n - 1 = 20 ----- n = 20 + 1 --- n = 21

Answer 2

Resposta:

$\textsf{Segue a resposta abaixo}$

Explicação passo-a-passo:

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

$\mathsf{ n=\dfrac{-66+6}{-3}+1}$

$\mathsf{n=\dfrac{-60}{-3}+1 }$

$\mathsf{n=20+1 }$

$\boxed{\boxed{ \mathsf{ n=21}}}$