0\\\\\sqrt{x}=\frac{1+\sqrt{21}}{2}\; \; ,\; \; x=\Big (\frac{1+\sqrt{21}}{2}\Big )^2=\frac{22+2\sqrt{21}}{4}=\frac{11+\sqrt{21}}{2}\\\\Otvst:\; \; x_1=0\; ,\; x_2=\frac{11+\sqrt{21}}{2}" alt="5\sqrt{x}=x\cdot (\sqrt{x}-1)\; \; ,\; \; ODZ:\; x\geq 0\\\\x\sqrt{x}-x-5\sqrt{x}=0\\\\\sqrt{x}\cdot (x-\sqrt{x}-5)=0\\\\a)\; \; \sqrt{x}=0\; \; \to \; \; x=0\\\\b)\; \; x-\sqrt{x}-5=0\\\\t=\sqrt{x}\geq 0\; \; ,\; \; t^2-t-5=0\; \; ,\\\\D=1+20=21\; \; ,\; \; t_1=\frac{1-\sqrt{21}}{2}<0\; ,\; t_2=\frac{1+\sqrt{21}}{2}>0\\\\\sqrt{x}=\frac{1+\sqrt{21}}{2}\; \; ,\; \; x=\Big (\frac{1+\sqrt{21}}{2}\Big )^2=\frac{22+2\sqrt{21}}{4}=\frac{11+\sqrt{21}}{2}\\\\Otvst:\; \; x_1=0\; ,\; x_2=\frac{11+\sqrt{21}}{2}" align="absmiddle" class="latex-formula">