1) х = 125
2) х = -2
3) х = 1/6
4) x = -1
5) x = -2
6) x = 4
7) x = 0.2
a) 2x-y=2;
2x^2-xy=6;
y=2x-2
2x^2-x(2x-2) =6;
2x^2-2x^2+2x=6;
2x=6;
x=3;
y=2*3-2=4.
Ответ: x=3
y=4