1楼小水的妈妈
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发表于 2009-6-15 15:23
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2.89×47＋1.53－1.4×1.1＋24×0.11＋288×0.53－0.1
=289×0.47+1.53-14×0.11+24×0.11+288×0.53－0.1
=(288+1)×0.47+1.53+(24-14)×0.11+288×0.53－0.1
=288×0.47+1×0.47+1.53+10×0.11+288×0.53－0.1
=288×(0.47+0.53)+(0.47+1.53)+(1.1-0.1)
=288×1+2+1
=288+2+1
=291.
