a)\(\frac{2^7.9^3}{6^5.8^2}\); \(\frac{6^3+3.6^2+3^3}{-13}\)
b)\(\left(\frac{3}{7}+\frac{1}{2}\right)^2\); \(\left(\frac{3}{4}-\frac{5}{6}\right)^2\); \(\left(-\frac{10}{3}\right)^5.\left(-\frac{6}{5}\right)^4\)
c)\(\left(1+\frac{2}{3}-\frac{1}{4}\right).\left(\frac{4}{5}-\frac{3}{4}\right)^2\); \(2:\left(\frac{1}{2}-\frac{2}{3}\right)^3\); \(9.9.\left(-\frac{1}{3}\right)^3+\frac{1}{3}\); \(\left(4.2^5\right):\left(2^3.\frac{1}{16}\right)\)