Rút gọn các phân số:
a) \(\frac{65656565}{118181817}\); \(\frac{123321123321}{205535205535}\); \(\frac{665933259992}{998899889988}\)
b)\(\frac{2109890109888}{46886468864}\); \(\frac{2716049379728395062}{1234567899876543210}\); \(\frac{11879669879658}{363663363663}\)