1) 4 – x = 2 1/7
х = 4 – 2 1/7
х = 1 6/7
4 – 1 6/7 = 2 1/7
2 1/7 = 2 1/7
2) x – 2 7/13 = 10 6/13
x = 10 6/13 + 2 7/13
x = 13
13 – 2 7/13 = 10 6/13
10 6/13 = 10 6/13
3) x + 4 8/11 = 11
x = 11 – 4 8/11
x = 6 3/11
6 3/11 + 4 8/11 = 11
11 = 11
4) 5 8/19 – x = 2 4/19
х = 5 8/19 – 2 4/19
х = 3 4/19
5 8/19 – 3 4/19 = 2 4/19
2 4/19 = 2 4/19