a)
\(\begin{array}{l}2023 - {25^2}:{5^3} + 27\\ = 2023 - {5^4}:{5^3} + 27\\ = 2023 - 5^{4-3} + 27\\ = 2023 -5 + 27\\ =2018+27\\= 2045\end{array}\)
b)
\(\begin{array}{l}60:\left[ {7.\left( {{{11}^2} - 20.6} \right) + 5} \right]\\ = 60:\left[ {7.\left( {121 - 120} \right) + 5} \right]\\ = 60:\left[ {7.1 + 5} \right]\\ = 60:12\\ = 5\end{array}\)