Две целых 5/14 минус одна целая 8/21 минус 1/3

2 5/14 - 1 8/21 - 1/3= (14*2+5)/14 - (21*1+8)/21 - 1/3= 33/14 - 29/21 - 1/3= (33*3)/(14*3) -(29*2)/(21*2) -(1*14)/(3*14)= 99/42 -58/42 -14/42= (99-58-14)/42= 27/42= 9/14.