в) 13,44:1\frac{3}{5}\cdot\left(4\frac{3}{7}+1\frac{2}{3}\right)\cdot2,1

в) $$13,44:1\frac{3}{5}\cdot\left(4\frac{3}{7}+1\frac{2}{3}\right)\cdot2,1=13,44:\frac{8}{5}\cdot\left(\frac{31}{7}+\frac{5}{3}\right)\cdot2,1=13,44:\frac{8}{5}\cdot\left(\frac{31\cdot3+5\cdot7}{21}\right)\cdot2,1=13,44:\frac{8}{5}\cdot\frac{93+35}{21}\cdot2,1=13,44:\frac{8}{5}\cdot\frac{128}{21}\cdot2,1=13,44\cdot\frac{5}{8}\cdot\frac{128}{21}\cdot2,1=\frac{1344}{100}\cdot\frac{5}{8}\cdot\frac{128}{21}\cdot\frac{21}{10}=\frac{1344\cdot5\cdot128\cdot21}{100\cdot8\cdot21\cdot10}=\frac{1344\cdot5\cdot128}{100\cdot8\cdot10}=\frac{1344\cdot5\cdot16}{100\cdot10}=\frac{1344\cdot80}{1000}=\frac{107520}{1000}=107,52$$

Ответ: $$107,52$$