А) 100 : 25 = 4
б) 18 : 0,2 = 18 : 2/10 = 18 * 10/2 = 9 * 10 = 90
в) 25 : 100 = 0,25 = 25 %
г) 0,2 : 18 = 2/10 : 18/1 = 2/10 * 1/18 = 1/10 * 1/9 = 1/90
д) 5/7 : 1/14 = 5/7 * 14/1 = 5/1 * 2/1 = 10
е) 2 4/7 : 1 15/21 = 18/7 : 36/21 = 18/7 * 21/36 = 1/1 * 3/2 = 3/2 = 1,5