Это образцы 6 34/39+7 38/39+5 37/39 8 713-7 2/13 7-9/11-4 8/11

1) 6 34/39 + 7 38/39 + 5 37/39 = (6 * 39 + 34)/39 + (7 * 39 + 38)/39 + (5 * 39 + 37)/39 = 268/39 + 311/39 + 232/39 = (268 + 311 + 232)/39 = 811/39 = 20 31/39.

2) 8 7/13 - 7 2/13 = (8 * 13 + 7)/13 - (7 * 13 + 2)/13 = 111/13 - 93/13 = (111 - 93)/13 = 18/13 = 1 5/13.

3) 7 - 9/11 - 4 8/11 = (7 * 11)/11 - 9/11 - (4 * 11 + 8)/11 = 77/11 - 9/11 - 52/11 = (77 - 9 - 52)/11 = 16/11 = 1 5/11.

4) 6 15/28 - (2 15/28 - 1 17/28) = 6 15/28 - 2 15/28 + 1 17/28 = (6 * 28 + 15)/28 - (2 * 28 + 15)/28 + (1 * 28 + 17)/28 = 183/28 - 71/28 + 45/21 = (183 - 71 + 45)/21 = 157/21 = 710/21.

5) 37 7/200 + Х = 39 4/200.

x = 39 4/200 - 37 7/200.

x = (39 * 200 + 4)/200 - (37 * 200 + 7)/200.

x = 7804/200 - 7407/200.

x = (7804 - 7407)/200.

x = 397/200 = 1 197/200.

Ответ: х = 1 197/200.

6) (Х + 24 3/19) - 3 18/19 = 21 17/19.

Х + 24 3/19 - 3 18/19 = 21 17/19.

x = (21 * 19 + 17)/19 - (24 * 19 + 3)/19 + (3 * 19 + 18)/19.

x = 416/19 - 459/19 + 75/19.

x = (416 - 459 + 75)/19.

x = 32/19 = 1 13/19.

Ответ: х = 1 13/19.