\[\left( \sqrt{19} \right)^{2} - \sqrt[6]{41^{6}} + \left( \sqrt[8]{20^{4}} \right)^{2} =\]
\[= 19 - 41 + \sqrt[8]{\left( 20^{4} \right)^{2}} =\]
\[= - 22 + \sqrt[8]{20^{8}} =\]
\[= - 22 + 20 = - 2\]