Thực hiện phép tính (tính hợp lí nếu có thể) \(\left( { - 80} \right) + 25 + \left( { - 20} \right) + 75\)

\(\left( { - 80} \right) + 25 + \left( { - 20} \right) + 75\)

\(\begin{array}{l} = \,\,\,\left[ {\left( { - 80} \right) + \left( { - 20} \right)} \right] + \left( {25 + 75} \right)\\ = \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, - 100\,\,\,\,\,\,\,\,\,\,\, + \,\,\,\,\,\,\,100\\ = \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,0\end{array}\)