13.9×9.9+1.39怎么简算?

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13.9×9.9+1.39怎么简算?
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13.9×9.9+1.39怎么简算?
13.9×9.9+1.39怎么简算?

13.9×9.9+1.39怎么简算?
13.9×9.9+1.39
=13.9×9.9+13.9×0.1
=13.9×(9.9+0.1)
=13.9×10
=139

原式=13.9×9.9+13.9×0.1=13.9×10=139

=13.9×9.9+13.9*0.1=13.9*(9.9+0.1)=139

13.9×9.9+1.39
=13.9×9.9+13.9×0.1
=13.9×(9.9+0.1)
=13.9×10
=139

解:原式=13.9*9.9+13.9*0.1
=13.9*(9.9+0.1)
=13.9*10
=139

1.39×99+1.39=(99+1)×1.39=139