用简便方法计算下面的算式(14+28+39)*(28+39+15)-(14+28+39+15)*(28+3)

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用简便方法计算下面的算式(14+28+39)*(28+39+15)-(14+28+39+15)*(28+3)
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用简便方法计算下面的算式(14+28+39)*(28+39+15)-(14+28+39+15)*(28+3)
用简便方法计算下面的算式(14+28+39)*(28+39+15)-(14+28+39+15)*(28+3)

用简便方法计算下面的算式(14+28+39)*(28+39+15)-(14+28+39+15)*(28+3)
(14+28+39)*(28+39+15)-(14+28+39+15)*(28+3)
=(14+28+39)*(28+39+15)-(14+28+39)*(28+3)-15*(28+3)
==(14+28+39)*(28+39+15-28-3)-15(28+3)
==81×51-15×31
=3666;