2\; \to \; 2-\sqrt5<0.\\\\
Kornej\; net." alt="x^2+2x\sqrt5+2x=-11\\\\x^2+2x(\sqrt5+1)+11=0\\\\D=4(\sqrt5+1)^2-4\cdot 11=4(5+2\sqrt5+1-11)=4(2\sqrt5-5)=\\\\=4\sqrt5(2-\sqrt5)<0\; \; ,\; \; t.k.\; \; \sqrt5>2\; \to \; 2-\sqrt5<0.\\\\
Kornej\; net." align="absmiddle" class="latex-formula">