решите систему уравнений х2-2ху=7,х-3у=-2

x^2 - 2xy = 7

x = 3y - 2

(3y - 2)^2 - 2*(3y-2)*y = 7; 

9y^2 - 12y + 4 - 6y^2 + 4y = 7

3Y^2 - 8y - 3 = 0

D = 64 - 4 * 3 * (-3) = 64 + 36 = 100

Y1 = (8 + 10): 6 =3

y2 = (8 - 10) : 6 = - 1/3

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x1 = 3* y1 - 2 = 3 * 3 - 2 = 7

x2 = 3 * y2 - 2 = 3 * (-1\3) - 2 = -1 - 2 = - 3

ОТВЕТ: X 1 = 7  y1 = 3

             X 2 = - 3  y2 = - 3