a, $\frac{3.5.7}{6.9.14}= \frac{3.5.7}{2.3.3^2.2.7}= \frac{5}{36}$
b, $\frac{2.5.13}{26.35}= \frac{2.5.13}{2.13.5.7}= \frac{1}{7}$
c, $\frac{4.7-4.5}{64}= \frac{4(7-5)}{2^6}= \frac{2^3}{2^6}= \frac{1}{8}$
d, $\frac{17.5+17}{3-20}= \frac{17(5+1)}{-17}= \frac{6}{-1}= -6$
e, $\frac{3^5.2^4}{8.36}= \frac{2^4.3^5}{2^5.3^2}= \frac{3^3}{2}= \frac{27}{2}$
f, $\frac{2^{10}.3^{10}-2^{10}.3^9}{2^9.3^{10}}= \frac{2^{10}(3^{10}-3^9)}{2^9.3^{10}}= \frac{2^{10}.3^{10}}{2^9.3^{10}} -\frac{2^{10}.3^9}{2^9.3^{10}}= 2- \frac{2}{3}= \frac{4}{3}$
