Решить уравнения: 2*х+3-х=15 7+3*у+2*у-1=46 9*а-6*а+4=16

2*х+3-х=15     7+3*у+2*у-1=46    9*а-6*а+4=16
2х-х=15-3        7-1+3у+2у=46       3а=16-4
х=12                 6+5у=46                 3а=12
                         5у=46-6                  а=4
                         5у=40
                         у=8