295-(31-2².5)² 205-[1200-(4²-2.3)³]:40 107-{38+[7.3²-24:6+(9-7)³]}:15

\(\begin{array}{l}
 + )\,\,295 – {\left( {31 – {2^2}.5} \right)^2}\\
 = 295 – {\left( {31 – 4.5} \right)^2} = 295 – {\left( {31 – 20} \right)^2}\\
 = 295 – {11^2} = 295 – 121 = 174\\
 + )\,205 – \left[ {1200 – {{\left( {{4^2} – 2.3} \right)}^3}} \right]:40\\
 = 205 – \left[ {1200 – {{\left( {16 – 6} \right)}^3}} \right]:40\\
 = 205 – \left( {1200 – {{10}^3}} \right):40\\
 = 205 – \left( {1200 – 1000} \right):40\\
 = 204 – 200:5\\
 = 204 – 4 = 200\\
 + )\,\,107 – \left\{ {38 + \left[ {{{7.3}^2} – 24:6 + {{\left( {9 – 7} \right)}^3}} \right]} \right\}:15\\
 = 107 – \left\{ {38 + \left[ {7.9 – 24:6 + {2^3}} \right]} \right\}:15\\
 = 107 – \left[ {38 + \left( {63 – 4 + 8} \right)} \right]:15\\
 = 107 – \left( {38 + 67} \right):15\\
 = 107 – 105:15\\
 = 107 – 7 = 100
\end{array}\)