х-1 х
-------- - ----------- = 1
3 4
4 (х-1) 3х
---------- - ------- = 1
12 12
4х -4 - 3х
------------------ = 1
12
х - 4
------------ =1
12
х - 4 = 1 * 12
х - 4 = 12
х = 12 + 4
х 16
16 - 1 16
------------ - ------------ = 1
3 4
15/3 - 16/4 = 1
60/12 - 48/12 = 1
12/12 = 1
1=1