$@Shin$
a,
$x$ - $\dfrac{1}{2}$ = $\dfrac{3}{4}$
$x$ = $\dfrac{3}{4}$ + $\dfrac{1}{2}$
$x$ = $\dfrac{5}{4}$
b,
$\dfrac{2}{3}$.$x$ + $\dfrac{1}{4}$ = $\dfrac{-2}{3}$
$\dfrac{2}{3}$.$x$ = $\dfrac{-2}{3}$ - $\dfrac{1}{4}$
$\dfrac{2}{3}$.$x$ = $\dfrac{-11}{12}$
$x$ = $\dfrac{-11}{12}$ : $\dfrac{2}{3}$
$x$ = $\dfrac{-11}{8}$
c, | $x$ + $\dfrac{5}{6}$| = $\dfrac{1}{3}$
⇒ $x$ + $\dfrac{5}{6}$ = $\dfrac{1}{3}$
⇒ $x$ = $\dfrac{1}{3}$ - $\dfrac{5}{6}$
⇒ $x$ = $\dfrac{-1}{2}$
⇒ $x$ + $\dfrac{5}{6}$ = $\dfrac{-1}{3}$
⇒ $x$ = $\dfrac{-1}{3}$ - $\dfrac{5}{6}$
⇒ $x$ = $\dfrac{-7}{6}$
