Question

решите систему уравнений срочно

Answer 1

$left { {{x^2-y^2=7} atop {xy=12}} right. ; left { {{frac{144}{y^2}-y^2=7} atop {x=frac{12}{y}}} right. ; left { {{144-y^4=7y^2} atop {x=frac{12}{y}}} right. \\y^4+7y^2-144=0\\D=625,; ; (y^2)_1=-16; <0,; ; (y^2)_2=9\\y_1=3,; y_2=-3\\x_1=4,; x_2=-4\\Otvet:; (4,3)),; (-4,-3)$