Решите систему уравнений {2х-3у=8, {х+у=9

[latex] left { {{2x-3y=8} atop {x+y=9}} ight. [/latex][latex] left { {{2x-3y=8} atop {x=9-y}} ight. [/latex][latex] left { {{2(9-y)-3y=8} atop {x=9-y}} ight. [/latex][latex] left { {{18-5y=8} atop {x=9-y}} ight. [/latex][latex] left { {{-5y=-10} atop {x=9-y} ight. [/latex]y=2 ; x=7.