$\text{HỌC TỐT!}$
$\text{20%x - x + $\dfrac{1}{5}$ = $\dfrac{3}{4}$}$
$\text{$\dfrac{2}{10}$x - x + $\dfrac{1}{5}$ = $\dfrac{3}{4}$}$
$\text{$\dfrac{-8}{10}x$ + $\dfrac{1}{5}$ = $\dfrac{3}{4}$}$
$\text{$\dfrac{-8}{10}x$ = $\dfrac{3}{4}$ - $\dfrac{1}{5}$}$
$\text{$\dfrac{-8}{10}x$ = $\dfrac{11}{20}$}$
$\text{x = $\dfrac{11}{20}$ : $\dfrac{-8}{10}$}$
$\text{x = $\dfrac{-11}{16}$}$
$\text{Vậy x = $\dfrac{-11}{16}$}$
