$\frac{15}{24}$ - $\frac{3}{8}$ - $\frac{1}{6}$
= $\frac{15}{24}$ - $\frac{9}{24}$ - $\frac{4}{24}$
= $\frac{2}{12}$
=$\frac{1}{12}$
( $\frac{5}{2}$ + $\frac{1}{3}$ ) : $\frac{(1 - 2) }{3}$
= ( $\frac{15}{6}$ + $\frac{2}{6}$ ) : $\frac{-1}{3}$
= $\frac{17}{6}$ : $\frac{-2}{6}$
= $\frac{17}{6}$ × $\frac{-6}{2}$
= $\frac{-17}{2}$
$\frac{13}{15}$ + $\frac{4}{7}$ - $\frac{101}{105}$
= $\frac{91}{105}$ + $\frac{60}{105}$ - $\frac{101}{105}$
= $\frac{50}{105}$
= $\frac{10}{21}$
$\frac{1}{2}$ : $\frac{1}{4}$ - $\frac{1}{6}$
= $\frac{1}{2}$ × $\frac{4}{1}$ - $\frac{1}{6}$
= 2 - $\frac{1}{6}$
= $\frac{11}{6}$
$\frac{5}{2}$ - $\frac{1}{3}$ × $\frac{9}{2}$ - $\frac{6}{7}$
= $\frac{5}{2}$ - $\frac{3}{2}$ - $\frac{6}{7}$
= 1 - $\frac{6}{7}$
= $\frac{1}{7}$
