(х+27)-12=42
х+27=42+12
х+27=54
х=54-27
х=27
28-t +35=53
63-53=t
10=t
t=10
х+27-12=42
х=42-27+12
28-t+35=53
28+35-53=t
(х+27)-12=42
х+27=42+12
х+27=54
х=54-27
х=27
28-t +35=53
63-53=t
10=t
t=10
(х+27)-12=42
х+27-12=42
х=42-27+12
х=27
28-t+35=53
28+35-53=t
t=10