1) (17/39 – x) + 5/39 = 14/39
17/39 – x = 14/39 – 5/39
17/39 – x = 9/39
x = 17/39 – 9/39
x = 8/39
2) 21/37 + (13/37 – x) = 34/37
13/37 – x = 34/37 – 21/37
13/37 – x = 13/37
х = 13/37 – 13/37
x = 0
3) (x – 8/47) – 12/47 = 13/47
x – 8/47 = 13/47 + 12/47
x – 8/47 = 25/47
x = 25/47 + 8/47
х = 33/47
4) 24/31 – (23/31 – x) = 9/31
23/31 – x = 24/31 – 9/31
23/31 – x = 15/31
х = 23/31 – 15/31
x = 8/31