To subtract \( \sqrt{11} \sqrt{19} - \sqrt{5} \sqrt{19} \), we first factor out the common term \( \sqrt{19} \):
\[ \sqrt{11} \sqrt{19} - \sqrt{5} \sqrt{19} = (\sqrt{11} - \sqrt{5}) \sqrt{19} \]
Thus, the simplified expression is
\[ (\sqrt{11} - \sqrt{5}) \sqrt{19} \]
This is the final result. If you have numerical values or more context you would like to discuss, please let me know!