Question

Задание из контрольной работы

Answer 1

$\left \{ {{x-y=40} \atop {\sqrt{x}-\sqrt{y}=10}} \right.\\\\\left \{ {{(\sqrt{x})^{2}-(\sqrt{y})^{2}=40} \atop {\sqrt{x}-\sqrt{y}=10}} \right.\\\\\left \{ {{(\sqrt{x}-\sqrt{y})(\sqrt{x}+\sqrt{y})=40} \atop {\sqrt{x}-\sqrt{y}=10}} \right.\\\\\left \{ {{10(\sqrt{x}+\sqrt{y})=40} \atop {\sqrt{x}-\sqrt{y}=10}} \right.\\\\+\left \{ {{\sqrt{x}+\sqrt{y}=4} \atop {\sqrt{x}-\sqrt{y}=10}} \right. \\-------\\2\sqrt{x}=14\\\\\sqrt{x}=7\\\\x=49\\\\\sqrt{y}=\sqrt{x}-10\\\\\sqrt{y}=7-10\\\\\sqrt{y}=-3$

Решений нет, так как √y ≥ 0