Question

пж очень надо))))!!!

Answer 1

$\displaystyle\bf\\\left \{ {{y^{2}-xy=12 } \atop {x^{2} -xy=-3}} \right.\\\\\\:\left \{ {{y\cdot(y-x)=12} \atop {x\cdot(x-y)=-3}} \right. \\----------\\-\frac{y}{x} =-4\\\\\\\frac{y}{x} =4\\\\\\y=4x\\\\\\x^{2} -x\cdot 4x=-3\\\\x^{2} -4x^{2} =-3\\\\-3x^{2} =-3\\\\x^{2} =1\\\\x_{1} =-1 \ \ \ ; \ \ \ x_{2} =1\\\\y_{1} =4\cdot(-1)=-4 \ \ \ ; \ \ \ y_{2} =4\cdot 1=4\\\\Otvet \ . \ (-1 \ ; \ -4) \ , \ (1 \ ; \ 4)$