Đáp án:
$y$ = $\dfrac{4}{5}$
Giải thích các bước giải:
$\dfrac{5}{4}$ - $y$ x $\dfrac{5}{6}$ = $\dfrac{1}{3}$ + $\dfrac{1}{4}$
$\dfrac{5}{4}$ - $y$ x $\dfrac{5}{6}$ = $\dfrac{7}{12}$
$y$ x $\dfrac{5}{6}$ = $\dfrac{5}{4}$ - $\dfrac{7}{12}$
$y$ x $\dfrac{5}{6}$ = $\dfrac{2}{3}$
$y$ = $\dfrac{2}{3}$ : $\dfrac{5}{6}$
$y$ = $\dfrac{4}{5}$
