2 x + 7*y = -4
2 2*x - 3*y = 21
2*x^2 - 3*y = 21
-2.81800930988317
-1.70588235294118
2.81800930988317
-1.70588235294118
x1 = 2.818009309883173 y1 = -1.705882352941176
x2 = -2.818009309883173 y2 = -1.705882352941176
x2 = -2.818009309883173 y2 = -1.705882352941176