Đáp án:
$\text{$\dfrac{2}{5}$ : (2x+$\dfrac{3}{4}$) = $\dfrac{-7}{10}$}$
$\text{<=> 2x + $\dfrac{3}{4}$ = $\dfrac{2}{5}$ : $\dfrac{-7}{10}$}$
$\text{<=> 2x + $\dfrac{3}{4}$ = $\dfrac{-4}{7}$ }$
$\text{<=> 2x = $\dfrac{-4}{7}$ - $\dfrac{3}{4}$ }$
$\text{<=> 2x = $\dfrac{-37}{28}$ }$
$\text{<=> x = $\dfrac{-37}{28}$ : 2 }$
$\text{<=> x = $\dfrac{-37}{56}$ }$
$\text{Vậy x = { $\dfrac{-37}{56}$ } }$
