Question

$7^x-7^{x-1}=8$

Answer 1

Resposta:

1+log(4/3)/log(7)

Explicação passo a passo:

7^x - 7^(x-1) = -6(-7^(x-1))

-6(-7^(x-1)) = 8

(-7^(x-1)) = -8/6

7^(x-1) = 4/3

aplicando log

(x-1) log(7) = log(4/3)

x-1 = log(4/3)/log(7)

x = 1+log(4/3)/log(7)

Answer 2

Resposta:

$\textsf{Leia abaixo}$

Explicação passo a passo:

$\sf 7^x - 7^{x - 1} = 8$

$\sf 7^x\left(1 - \dfrac{1}{7}\right) = 8$

$\sf 7^x\:.\:\dfrac{6}{7} = 8$

$\sf 7^x\:.\:6 = 56$

$\sf 7^x = \dfrac{28}{3}$

$\sf log\:7^x = log\:\dfrac{28}{3}$

$\boxed{\boxed{\sf x = log_7\left(\dfrac{28}{3}\right)}}$