Даю 35 баллов .Решите методом подстановки.

[latex]1); ; left { {{-3x+0,5y=2; |cdot 2} atop {2x-y=0}} ight. ; left { {{-6x+y=4} atop {2x-y=0}} ight. ; left { {{-6x+2x=4} atop {y=2x}} ight. ; left { {{-4x=4} atop {y=2x}} ight. ; left { {{x=-1} atop {y=-2}} ight. [/latex][latex]2); ; left { {{frac{1}{6}x-frac{1}{5}y=1|cdot 30} atop {frac{1}{3}x+frac{1}{10}y=2|cdot 30}} ight. ; left { {{5x-6y=30} atop {10x+3y=60}} ight. ; left { {{5x=30+6y} atop {2cdot 5x+3y=60}} ight. ; left { {{5x=30+6y} atop {2cdot (30+6y)+3y=60}} ight. \\ left { {{5x=30+6y} atop {60+15y=60}} ight. ; left { {{5x=30+6y} atop {15y=0}} ight. ; left { {{5x=30} atop {y=0}} ight. ; left { {{x=6} atop {y=0}} ight. [/latex]