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14.2×4数学公式+5数学公式×14.2

解:14.2×4+5×14.2,
=14.2×(4+5),
=14.2×10,
=142.
分析:利用乘法的分配律变成14.2×(4+5)计算简便.
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.
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