Решите систему ур-ий методом подстановки (20 баллов!!!!) у-2х=1 6х-у=7 _____ х = 2 – у, 3х – 2у = 11 _____ х + у = 6, 3х – 5у = 2.

[latex] 1) \left { {{y-2x=1} atop {6x-y=7}} ight. \ left { {{y=1+2x} atop {6x-(1+2x)=7}} ight. \ left { {{y=1-2x} atop {4x=8}} ight. \ left { {{y=1-2x} atop {x=2}} ight. \ left { {{y=5} atop {x=2}} ight. \ 2) \ left { {{x=2-y} atop {3x-2y=11}} ight. \ left { {{x=2-y} atop {3(2-y)-2y=11}} ight. \ left { {{x=2-y} atop {y=-1}} ight. \ left { {{x=3} atop {y=-1}} ight. [/latex][latex]3) \ left { {{x+y=6} atop {3x-5y=2}} ight. \ left { {{y=6-x} atop {3x-5(6-x)=2}} ight. \ left { {{y=6-x} atop {8x=32}} ight. \ left { {{y=6-x} atop {x=4}} ight. \ left { {{y=2} atop {x=4}} ight. [/latex]