1) 52/63 - x/63 = 29/72
Первым шагом уберем дроби, умножив обе части уравнения на 63:
52 - x = 29 63 / 72
52 - x = 29 7 / 8
52 - x = 203 / 8
x = 52 - 203 / 8
x = 416 / 8 - 203 / 8
x = 213 / 8

Ответ: x = 213 / 8

2) (29/42 - a) - 13/42 = 11/42
(29 - 42a) / 42 - 13/42 = 11/42
29 - 42a - 13 = 11
29 - 13 - 42a = 11
16 - 42a = 11
-42a = 11 - 16
-42a = -5
a = -5 / (-42)
a = 5 / 42

Ответ: a = 5 / 42

3) 15/17 - (b - 3/17) = 6/17
15/17 - b + 3/17 = 6/17
15 + 3 - 17b = 6
18 - 17b = 6
-17b = 6 - 18
-17b = -12
b = -12 / (-17)
b = 12 / 17

Ответ: b = 12 / 17

4) 29/43 - (m + 13/43) = 5/43
29/43 - m - 13/43 = 5/43
29 - 43m - 13 = 5
29 - 13 - 43m = 5
16 - 43m = 5
-43m = 5 - 16
-43m = -11
m = -11 / (-43)
m = 11 / 43

Ответ: m = 11 / 43