如题所述
39x5x4=39x20=39+39+39+39+39+39+39+39+39+39+39+39+39+3939+39+39+39+39+39=20+20+20+20+20+20+20+20+20+20+20+20+20+20+20+20+20+20+20+20+20+20+20+......=390x2=39x20=39x5x4
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第1个回答 2015-04-11
39*5*4
=39*(5*4)
=39*20
=780本回答被网友采纳
=39*(5*4)
=39*20
=780本回答被网友采纳