№5:
1).502/10 : 251/6 = 502/10 * 6/251 = 6/5
2). 1804/100 : 451/9 = 1804/100 * 9/451 = 9/25
3). 6/5 - 9/25 = 30/25 - 9/25 = 21/25 = 0,84
№6:
1). 27/1000 : 81/100 = 27/1000 * 100/81 = 1/30
2). 9/100 * 10/27 = 1/30
3). 1/30 + 1/30 = 2/30
4). 2/30 * 3/100 = 1/500 = 0,002
5). 0,002 + 0,998 = 1