Tính giá trị của các biểu thức sau

a) $\left(\frac{2}{3}+\frac{1}{6}\right):\frac{5}{4}+\left(\frac{1}{4}+\frac{3}{8}\right):\frac{5}{2}$

$=\left(\frac{4}{6}+\frac{1}{6}\right):\frac{5}{4}+\left(\frac{2}{8}+\frac{3}{8}\right):\frac{5}{2}$

$=\frac{5}{6}:\frac{5}{4}+\frac{5}{8}:\frac{5}{2}$

$=\frac{5}{6}.\frac{4}{5}+\frac{5}{8}.\frac{2}{5}$

$=\frac{5.4}{6.5}+\frac{5.2}{8.5}$

$=\frac{2}{3}+\frac{1}{4}$

$=\frac{8}{12}+\frac{3}{12}$

$=\frac{11}{12}$

b) $\frac{5}{9}:\left(\frac{1}{11}-\frac{5}{22}\right)+\frac{7}{4}.\left(\frac{1}{14}-\frac{2}{7}\right)$

$=\frac{5}{9}:\left(\frac{2}{22}-\frac{5}{22}\right)+\frac{7}{4}.\left(\frac{1}{14}-\frac{4}{14}\right)$

$=\frac{5}{9}:\frac{-3}{22}+\frac{7}{4}.\frac{-3}{14}$

$=\frac{5}{9}.\frac{22}{-3}+\frac{7.\left(-3\right)}{4.14}$

$=\frac{5.22}{9.\left(-3\right)}+\frac{-3}{8}$

$=\frac{110}{-27}+\frac{-3}{8}$

$=\frac{-110}{27}+\frac{-3}{8}$

$=\frac{-880}{216}+\frac{-81}{216}$

$=\frac{-961}{216}$