Question

Quantos termos tem a P.A. (4; 4,2; 4,4....8)

a)25

b)24

c)23

d)21.

Answer 1

Explicação passo-a-passo:

$r = 4.2 - 4 = 0.2$

$8 = 4 + (n - 1)(0.2)$

$8 = 4 + 0.2n - 0.2$

$8 = 3.8 + 0.2n$

$8 - 3.8 = 0.2n$

$4.2 = 0.2n$

$n = \frac{4.2}{0.2}$

$n = 21$

Letra D