Question

5) A solução da equação abaixo, é: *


$x + \frac{x}{3} + \frac{x}{9} + \frac{x}{27} ... = 60$

A) 37
B) 40
C) 44
D) 50
E) 51
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Answer 1

Resposta:

$x +\frac{x}{3}+\frac{x}{9}+\frac{x}{27}= 60 \\\\x\cdot \:27+\frac{x}{3}\cdot \:27+\frac{x}{9}\cdot \:27+\frac{x}{27}\cdot \:27=60\cdot \:27\\\\x\cdot \:27+9x+3x+x=1620\\\\40x=1620\\\\\frac{40x}{40}=\frac{1620}{40}\\\\x=\frac{81}{2}\\\\x= 40$

Answer 2

Resposta:

X = 40

Explicação passo a passo:

PG:

Q = a2/a1= x/3÷ x

Q = x/3 . 1/x

Q = 1/3

Sn = a1 / ( 1 - q)

60 = x / ( 1 - 1/3)

60.(1 - 1/3) = x

60 - 60/3 = x

60 - 20 = x

X = 40