$\sqrt{ 6+2\sqrt{ 3 }+2\sqrt{ 2 }+2\sqrt{ 6 } }-\frac{ 1 }{ \sqrt{ {\left( \sqrt{ 2 }-\sqrt{ 3 } \right)}^{2} } }$
Reduce the index of the radical and exponent with $2$$\sqrt{ 6+2\sqrt{ 3 }+2\sqrt{ 2 }+2\sqrt{ 6 } }-\frac{ 1 }{ \sqrt{ 3 }-\sqrt{ 2 } }$
Rationalize the denominator$\sqrt{ 6+2\sqrt{ 3 }+2\sqrt{ 2 }+2\sqrt{ 6 } }-\left( \sqrt{ 3 }+\sqrt{ 2 } \right)$
When there is a $-$ in front of an expression in parentheses, change the sign of each term of the expression and remove the parentheses$\begin{align*}&\sqrt{ 6+2\sqrt{ 3 }+2\sqrt{ 2 }+2\sqrt{ 6 } }-\sqrt{ 3 }-\sqrt{ 2 } \\&\approx1\end{align*}$