Выполните вычитание : а) 7 8/9-2 2/3 , в) 15 8/21-6 5/14 , б) 4 17/18-2 7/12 , г) 5 5/9-2 4/7

а) 71/9 - 8/3 = 71/9 - 24/9 = 47/9 = 5 2/9б) 89/18 - 31/12 = 178/18 - 93/36 = 85/36 = 2 13/36в) 323/21 - 89/14 = 646/42 - 267/42 = 379/42 = 9 1/42г) 50/9 - 18/7 = 350/63 - 162/63 = 188/63 = 2 62/63