Đáp án:
Giải thích các bước giải:
$\text{e, $(\frac{-2}{3})^{2x-1}$ = $\frac{-8}{27}$ }$
$\text{$(\frac{-2}{3})^{2x-1}$ = ($\frac{-2}{3}$)³}$
$\text{⇒2x-1=3}$
$\text{2x=4}$
$\text{x=2}$
$\text{Vậy x=2}$
$\text{f, $(x-7)^{x+1}$ = $(x-7)^{x+11}$ }$
$\text{$(x-7)^{x+1}$ : $(x-7)^{x+1}$= $(x-7)^{x+11}$ : $(x-7)^{x+1}$}$
$\text{$(x-7)^{x+1-x-1}$ =$(x-7)^{x+11-x-1}$ }$
$\text{$(x-7)^{0}$ = $(x-7)^{10}$ }$
$\text{1= $(x-7)^{10}$ }$
$\text{⇒1=x-7}$
$\text{⇒x-7=1}$
$\text{x=1+7}$
$\text{x=8}$
$\text{Vậy x=8}$
