Thực hiện phép tính (tính hợp lí nếu có thể):

a) \(125:25 + 12.4\)

\( = 5 + 48\)

\( = 53\).

b) \(43 + \left( { - 100} \right) + \left( { - 43} \right) + 150\)

\[ = \left[ {43 + \left( { - 43} \right)} \right] + \left[ {\left( { - 100} \right) + 150} \right]\]

\( = 0 + 50\)

\( = 50\).

c) \({\left( { - 5} \right)^2}.{\left( { - 3} \right)^3}{.2^3}\)

\( = 25.\left( { - 27} \right).8\)

\( = \left( {25.8} \right).\left( { - 27} \right)\)

\( = 200.\left( { - 27} \right)\)

\( =  - 5400\).

d) \[ - 48 + 48.\left( { - 78} \right) + 48.\left( { - 21} \right)\]

\[ = 48.\left( { - 1} \right) + 48.\left( { - 78} \right) + 48.\left( { - 21} \right)\]

\( = 48.\left[ {\left( { - 1} \right) + \left( { - 78} \right) + \left( { - 21} \right)} \right]\)

\( = 48.\left( { - 100} \right)\)

\( =  - 4\,800\).