a) $x\;-\;\frac{3}{5} = \frac{1}{2} $

$\Rightarrow x = \frac{1}{2}\;+\;\frac{3}{5}$.

$\Rightarrow x = \frac{5}{10}\;+\;\frac{6}{10}$.

$\Rightarrow x = \frac{5\;+\;6}{10}$.

$\Rightarrow x = \frac{11}{10}$.

b) $\frac{-5}{8}\;-\;x = \frac{7}{24}\;+\;\frac{-1}{6}$.

$\Rightarrow -x = \frac{7}{24}\;+\;\frac{-1}{6}\;+\;\frac{5}{8}$.

$\Rightarrow x = -(\frac{7}{24}\;+\;\frac{-1}{6}\;+\;\frac{5}{8})$.

$\Rightarrow x = -(\frac{7}{24}\;+\;\frac{-4}{24}\;+\;\frac{15}{24})$.

$\Rightarrow x = -(\frac{7\;+\;(-4)\;+\;15}{24})$.

$\Rightarrow x = -(\frac{18}{24})$.

$\Rightarrow x = -(\frac{3}{4})$.