2) (5/12 - х) : 1/2 = 2/9
5/12 - х = 2/9 * 1/2
5/12 - х = 1/9
- х = 1/9 - 5/12
- х = 4/36 - 15/36
- х = -11/36
х = 11/36
4) 4/15 - ( у + 3/25 ) = 1/25
4/15 - у - 3/25 = 1/25
- у = 1/25 - 4/15 + 3/25
- у = 4/25 - 4/15
- у = 12/75 - 20/75
- у = - 8/75
у = 8/75
6) 3 1/16 : (х - 5/16 ) = 7/8
х - 5/16 = 3 1/16 : 7/8
х - 5/16 = 49/16 : 7/8
х - 5/16 = 49/16 * 8/7
х - 5/16 = 7/2
х - 5/16 = 3 1/2
х = 3 1/2 + 5/16
х = 3 8/16 + 5/16
х = 8 13/16