Развежите систему уравнений: {х+4у=6 {х^2-3ху-у^2=-3

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Развежите систему уравнений: {х+4у=6 {х^2-3ху-у^2=-3


Алгебра (12 баллов) | 88 просмотров
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\left \{ {{x + 4y = 6} \atop {x^2 - 3xy - y^2 = -3}} \right.  ⇔ \left \{ {{x = 6 - 4y} \atop {(x - y)(x + y) - 3xy = -3}} \right.\left \{ {{x = 6 - 4y} \atop {(6 - 4y - y)(6 - 4y + y) - 3(6 - 4y)y = -3}} \right.

\left \{ {{x = 6 - 4y} \atop {(6 - 5y)(6 - 3y) - 18y + 12y^2 = -3}} \right.\left \{ {{x = 6 - 4y} \atop {6(6 - 5y) - 3y(6 - 5y) - 18y + 12y^2 = -3}} \right.

\left \{ {{x = 6 - 4y} \atop {36 - 30y - 18y + 15y^2 - 18y + 12y^2 = -3}} \right.\left \{ {{x = 6 - 4y} \atop {27y^2 - 66y + 39 = 0}} \right.\left \{ {{x = 6 - 4y} \atop {9y^2 - 22y + 13 = 0}} \right.

\left \{ {{x = 6 - 4y} \atop {y = 1}} \right.\left \{ {{x = 2} \atop {y = 1}} \right.

   \left \{ {{x = 6 - 4y} \atop {y = \frac{13}{9}}} \right.    \left \{ {{x = \frac{2}{9}} \atop {y = \frac{13}{9}}} \right.

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