3/17+11/14-2/21=1 5/42 3/7+11/14=6/14+11/14=17/14=1 3/14 1 3/14-2/21-17/14-2/21-51/42-4/42-47/42= 1 5/42
13/18-1/24-(29/12+6/36)=13/18-2 7/12=-1 65/72 29/12+6/36-87/36+6/36-93/36-2 21/36=2 7/12 13/18-1\24=52/72-3/72=49/72 49/72-2 7/12=49/72-31/12-49/72-186/72= -137/72= -1 65/72