А) 4/7 * 5/24 : 1 1/14 = 1/9
1) 4/7 * 5/24 = 5/42
2) 5/42 : 1 1/14 = 5/42 : 15/14 = 5/42 * 14/15 = 1/9
б) 25 * 7/15 : 7/9 = 15
1) 25 * 7/15 = 35/3 = 11 2/3
2) 11 2/3 : 7/9 = 35/3 * 9/7 = 15
в) 7/18 : 20/21 : 5/12 = 49/50
1) 7/18 : 20/21 = 7/18 * 21/20 = 49/120
2) 49/120 : 5/12 = 49/120 * 12/5 = 49/50
г) 5/9 * 2 1/4 : 20 = 1/16
1) 5/9 * 2 1/4 = 5/9 * 9/4 = 5/4 = 1 1/4
2) 1 1/4 : 20 = 5/4 * 1/20 = 1/16