$\Bigg(-\dfrac{5}{8}+\dfrac{7}{6}-\dfrac{4}{5}\Bigg)-\Bigg(\dfrac{5}{6}-\dfrac{7}{8}-\dfrac{7}{5}\Bigg)+\Bigg(\dfrac{3}{4}+\dfrac{5}{3}+\dfrac{12}{5}\Bigg)$
$=\Bigg(-\dfrac{5}{8}+\dfrac{7}{6}-\dfrac{4}{5}\Bigg)-\Bigg(\dfrac{5}{6}-\dfrac{7}{8}-\dfrac{7}{5}\Bigg)+\Bigg(\dfrac{6}{8}+\dfrac{10}{6}+\dfrac{12}{5}\Bigg)$
$=\Bigg(-\dfrac{5}{8}+\dfrac{7}{8}+\dfrac{6}{8}\Bigg)+\Bigg(\dfrac{7}{6}-\dfrac{5}{6}+\dfrac{10}{6}\Bigg)+\Bigg(-\dfrac{4}{5}+\dfrac{7}{5}+\dfrac{12}{5}\Bigg)$
$=1+2+3$
$=6$
