11/2:9/2+13/2:(10/7+11/3)-(17/3-33/16:11/1)=10/7+11/3=30/21+77/21=107/21
17/3-33/16:11/1=272/48-99/48:528/48=99/48:528/48=99/48*48/528=89/1*1/48=89/48
272/48-89/48=107/21-183/48=1712/336-1281/336=431/336:13/2=431/336*2/13 =862/4368
11/2:9/2=11/2*2/9=11/1*1/9=11/9+862/4368=11/3+862/1456=16016/4368+2586/4368=18602/4368