$18\frac{21}{53} * \frac{27}{34} * 42\frac{2}{5} * 47\frac{2}{9} - \frac{125}{161} * 8\frac{216}{617} * 15\frac{17}{40} * 22\frac{31}{36} = \frac{53 * 18 + 21}{53} * \frac{27}{34} * \frac{42 * 5 + 2}{5} * \frac{47 * 9 + 2}{9} - \frac{125}{161} * \frac{8 * 617 + 216}{617} * \frac{15 * 40 + 17}{40} * \frac{36 * 22 + 31}{36} = \frac{3 * (53 * 6 + 7)}{53} * \frac{9 * 3}{17 * 2} * \frac{2 * (21 * 5 + 1)}{5} * \frac{47 * 9 + 2}{3 * 3} - \frac{5 * 25}{23 * 7} * \frac{8 * (617 + 27)}{617} * \frac{15 * 40 + 17}{8 * 5} * \frac{36 * 22 + 31}{36} = \frac{53 * 6 + 7}{53} * \frac{9}{17} * \frac{21 * 5 + 1}{5} * \frac{47 * 9 + 2}{1} - \frac{25}{23 * 7} * \frac{617 + 27}{617} * \frac{15 * 40 + 17}{1} * \frac{36 * 22 + 31}{36} = \frac{318 + 7}{53} * \frac{9}{17} * \frac{105 + 1}{5} * \frac{432 + 2}{1} - \frac{25}{23 * 7} * \frac{617 + 27}{617} * \frac{600 + 17}{1} * \frac{792 + 31}{36} = \frac{325}{53} * \frac{9}{17} * \frac{106}{5} * \frac{425}{1} - \frac{25}{23 * 7} * \frac{644}{617} * \frac{617}{1} * \frac{823}{36} = \frac{65 * 5}{53} * \frac{9}{17} * \frac{53 * 2}{5} * \frac{25 * 17}{1} - \frac{25}{23 * 7} * \frac{23 * 7 * 4}{1} * \frac{1}{1} * \frac{823}{36} = \frac{65 * 1}{1} * \frac{9}{1} * \frac{1 * 2}{1} * \frac{25 * 1}{1} - \frac{25}{1} * \frac{1 * 4}{1} * \frac{1}{1} * \frac{823}{36} = 65 * 9 * 2 * 25 - 25 * 4 * \frac{823}{4 * 9} = 25 * (65 * 9 * 2 - \frac{823}{9}) = 25 * (1170 - \frac{823}{9}) = 25 * (1170 - \frac{823}{9}) = 25 * (1170 - 91\frac{4}{9}) = 25 * (1078\frac{9}{9} - \frac{4}{9}) = 25 * 1078\frac{5}{9} = 26963\frac{8}{9}$