0\; \Big ]=4-\sqrt5" alt="\boxed{\sqrt{x^2}=|x|=\left \{ {{x\; ,\; esli\; x\geq 0\; ,} \atop {-x\; ,\; esli\; x<0\; .}} \right. }\\\\\\\sqrt{(4-\sqrt5)^2}=|4-\sqrt5|=\Big [\, \sqrt5\approx 2,24\; \; \to \; \; (4-\sqrt5)>0\; \Big ]=4-\sqrt5" align="absmiddle" class="latex-formula">