х^2-2 у=3,

х^2 у=27 система

X^2 = 3 + 2Y

Y * (3 + 2Y) = 27

3Y + 2Y^2 = 27

2Y^2 + 3Y - 27 = 0

D = 9 - 4*2 * (-27) = 9 + 216 = 225; V D = 15

Y1 = (- 3 + 15) : 4 = 12 : 4 = 3

Y2 = (- 18) : 4 = (- 4.5)

X^2 = 3 + 2Y - - - > X = V (3 + 2Y)

X1 = V (3 + 6) = V 9 = 3

X2 = V 3 - 9 = V (- 6) - не может быть