Выполните действия: 9 5/21-(10-3 5/28)

1) 
2) 

9целых 5/21 = (9*21+5)/21= 194/21
3целых 5/28 = (3*28+5)/28 = 89/28
(10-3 5/28) = 10-(89/28) = (10*28-89)/28 = 191/28
9 5/21-(10-3 5/28) = 194/21-191/28 = (194*28 -191*21)/21*28 = 1421/588 = 203/84 = 29/12 =2целых 5/12