Question

EQUAÇÃO EXPONENCIAL:
$7^{X}$+$7^{X-1}$=8

Answer 1

$7^{x}+ 7^{x-1} =8 \\ 7^{x}+7^{x}.7^{-1}=8 \\ 7^{x}+7^{x}. \frac{1}{7} =8 \\ 7^{x}.(1+\frac{1}{7} )=8 \\ 7^{x}.\frac{8}{7}=8 \\ 7^{x}=8.\frac{7}{8} \\ 7^{x}=7 \\ 7^{x}= 7^{1} \\ \\ x=1$

Answer 2

$7^{x}+ \frac{ 7^{x} }{7} = 8$
----------------------------- x 7
$7.7^{x} + 7^{x} = 8.7$
$7^{x} (7 + 1 ) = 8.7$
      $7^{x} .8 = 8.7$
            $7^{x} = 7$
            x = 1