Rút gọn phân số:
a)\(\frac{9}{33-6}\)
b)\(\frac{7}{10^2+6\times10^2}\)
c)\(\frac{11\times12+33\times36+55\times60}{22\times24+66\times72+110\times120}\)
d)\(\frac{9^4\times27^5\times3^6\times4^4}{3^8\times81^4\times243\times8^2}\)
e)\(\frac{199919991999}{200020002000}\)