1) Z = 8 8\11 - 3 9\11 = 7 19\11 - 3 9\11 = 4 10\11
2) Y = 4\5 + 4 3\5 = 4 7\5 = 5 2\5 = 5.4
3) X - 2 17\27 = 8 16\27 - 8 5\27
X - 2 17\27 = 11\27
X = 11\27 + 2 17\27
X = 2 28\27
X = 3 1\27
HOK(28,21)=28·3=84; НОД(28,21)=7, 84·7=588, 28·21=588,Т.Е.
НОК(а,б)×НОД(а,б)=а×б.