Tính một cách hợp lí:
\(\begin{array}{*{20}{l}}{a){\rm{ }}18,65 + 281,35 - 26,75 - 13,25;}\\{b){\rm{ }}38,25 - 18,25 + 21,64 - 11,64 + 9,93;}\\{c){\rm{ }}\left( {72,69 + 18,47} \right) - \left( {8,47 + 22,69} \right)}\\{d){\rm{ }}114,02 - \left( {114,37{\rm{ }} - {\rm{ }}85,98} \right).}\end{array}\)
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\(\begin{array}{*{20}{l}}\begin{array}{l}a){\rm{ }}18,65 + 281,35 - 26,75 - 13,25\\ = \left( {18,65 + 281,35} \right) - \left( {26,75 + 13,25} \right)\\ = 300 - 40\\ = 260\end{array}\\\begin{array}{l}b){\rm{ }}38,25 - 18,25 + 21,64 - 11,64 + 9,93\\ = \left( {38,25 - 18,25} \right) + \left( {21,64 - 11,64} \right) + 9,93\\ = 20 + 10 + 9,93\\ = 39,93\end{array}\\\begin{array}{l}c){\rm{ }}\left( {72,69 + 18,47} \right) - \left( {8,47 + 22,69} \right)\\ = 72,69 + 18,47 - 8,47 - 22,69\\ = \left( {72,69 - 22,69} \right) + \left( {18,47 - 8,47} \right)\\ = 50 + 10\\ = 60\end{array}\\\begin{array}{l}d){\rm{ }}114,02 - \left( {114,37{\rm{ }} - {\rm{ }}85,98} \right)\\ = 114,02 - 114,37{\rm{ + }}85,98\\ = \left( {114,02\,{\rm{ + }}85,98} \right) - 114,37\\ = 200 - 114,37\\ = 85,63{\rm{ }}\end{array}\end{array}\)