Thực hiện phép tính: a) 34.68 + 32.34;  b) 120 - 2^2.5 + 4^7:4^5  

a) \(34.68 + 32.34\)

\( = 34.\left( {68 + 32} \right)\)

\( = 34.100\)

\( = 3400\).

b) \(120 - {2^2}.5 + {4^7}:{4^5}\)

\( = 120 - 4.5 + {4^2}\)

\( = 120 - 20 + 16\)

\( = 100 + 16\)

\( = 116\).

c) \(36:\left\{ {180:\left[ {50 - \left( {{5^3} - 15.7} \right)} \right]} \right\}\)

\[ = 36:\left\{ {180:\left[ {50 - \left( {125 - 105} \right)} \right]} \right\}\]

\[ = 36:\left\{ {180:\left[ {50 - 20} \right]} \right\}\]

\[ = 36:\left\{ {180:30} \right\}\]

\[ = 36:6\]

\( = 6\).