\[\boxed{\mathbf{94}.}\]
\[1)\ \sqrt{4x^{2} + 12xy + 9y^{2}} =\]
\[= \sqrt{(2x + 3y)^{2}} = |2x + 3y|\]
\[2)\ \sqrt{\left( 5 - \sqrt{23} \right)^{2}} = \left| 5 - \sqrt{23} \right| =\]
\[= 5 - \sqrt{23}\]
\[3)\ \sqrt{\left( \sqrt{23} - 5 \right)^{2}} = \left| \sqrt{23} - 5 \right| =\]
\[= 5 - \sqrt{23}\]
\[4)\ \sqrt{(a - b)^{2}} = |a - b| =\]
\[= a - b;\ \ a \geq b.\]
\[5)\ \sqrt{(a - b)^{2}} = |a - b| =\]
\[= b - a;\ \ a \leq b.\]