Thực hiện phép tính (tính hợp lí nếu có thể):a) 60,7 + 25,5 - 38,7; b) - 7/16 + 3/4

a) \[60,7 + 25,5--38,7\]

\( = \left( {60,7-38,7} \right) + 25,5\)

\( = 22 + 25,5\)

\( = 47,5\)

b) \(\frac{{ - 7}}{{16}} + \frac{3}{4}\)\( = \frac{{ - 7}}{{16}} + \frac{{12}}{{16}}\)\( = \frac{5}{{16}}\).

c) \(3,4.\left( { - 23,68} \right) - 3,4.45,12 + \left( { - 31,2} \right).3,4\)

\[ = 3,4.\left[ {\left( { - 23,68} \right) - 45,12 + \left( { - 31,2} \right)} \right]\]

\[ = 3,4.\left[ { - 100} \right]\]

\[ =  - 340\].

d) \({\left( { - 2} \right)^3}.\frac{{ - 1}}{{24}} + \left( {\frac{4}{5} - 1,2} \right):\frac{2}{{15}}\)

\( = \left( { - 8} \right).\frac{{ - 1}}{{24}} + \left( {\frac{4}{5} - \frac{6}{5}} \right).\frac{{15}}{2}\)

\( = \frac{1}{3} + \frac{{ - 2}}{5}.\frac{{15}}{2}\)

\( = \frac{1}{3} + \left( { - 3} \right)\)

\( = \frac{{ - 8}}{3}\).