1) х - 3 3
----------- = ------
8 5
5 * (х - 3) = 3 * 8
5х - 15 = 24
5х = 24 + 15
5х = 39
х = 39 : 5
х = 7 4/5
2) 20 2
----------- = ----
х + 9 3
2 * (х + 9) = 3 * 20
2х + 18 = 60
2х = 60 - 18
2х = 42
х = 42 : 2
х = 21
3) 2х + 7 5
---------- = ----
18 12
12 * (2х + 7) = 5 * 18
24х + 84 = 90
24х = 90 - 84
24х = 6
х = 6 : 24
х = 1/4
4) 7 2
------------- = -----
38 - 3х 9
2 * (38 - 3х) = 7 * 9
76 - 6х = 63
6х = 76 - 63
6х = 13
х = 13/6
х = 2 1/6
5) 0,5 3
-------------- = 1 -----
2,5х - 4 4
0,5 7
-------------- = -----
2,5х - 4 4
7 * (2,5х - 4) = 0,5 * 4
17,5х - 28 = 2
17,5х = 2 + 28
17,5х = 30
х = 30 : 17,5
х = 30 : 175/10
х = 30/1 * 10/175
х = 300/175
х = 12/7
х = 1 5/7
6) 1/3х - 2 5
--------------- = ------
6 12
12 * (1/3х - 2) = 6 * 5
4х - 24 = 30
4х = 30 + 24
4х = 54
х = 54 : 4
х = 13,5