495.
2) (3 9/16 - у) + 4 9/16 = 5 7/16
3 9/16 - у = 5 7/16 - 4 9/16
3 9/16 - у = 4 23/16 - 4 9/16
3 9/16 - у = 14/16
у = 3 9/16 - 14/16
у = 2 25/16 - 14/16
у = 2 11/16
3) 13 16/27 + (х - 2 17/27) = 30 5/27
х - 2 17/27 = 30 5/27 - 13 16/27
х - 2 17/27 = 29 32/27 - 13 16/27
х - 2 17/27 = 16 16/27
х = 16 16/27 + 2 17/27
х = 18 33/27
х = 19 6/27 = 19 2/9
4) (у - 2 4/25) + 4 7/25 = 14 6/25
у - 2 4/25 = 14 6/25 - 4 7/25
у - 2 4/25 = 13 31/25 - 4 7/25
у - 2 4/25 = 9 24/25
у = 9 24/25 + 2 4/25
у = 11 28/25
у = 12 3/25