\(27.77+24.27-27\)
\(=27.\left(77+24-1\right)\)
\(=27.100\)
\(=2700\)
\(174\div\left\{2\left[36+\left(4^2-23\right)\right]\right\}\)
\(=174\div\left\{2\left[36+\left(16-23\right)\right]\right\}\)
\(=174\div\left\{2\left[36+\left(-7\right)\right]\right\}\)
\(=174\div\left\{2.29\right\}\)
\(=174\div58\)
\(=3\)
\(3^2.4-\left[30-\left(5-2\right)^2\right]\)
\(=9.4-\left[30-3^2\right]\)
\(=36-\left[30-9\right]\)
\(=36-21\)
\(=15\)