43×4.7+47×5.

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43×4.7+47×5.

43×4.7+47×5.
43×4.7+47×5.

43×4.7+47×5.
=43x4.7+4.7x10x5.7
=43x4.7+4.7x57
=4.7x(43+57)
=4.7x100
=470

原式=4.7x(43+57)=470

43×4.7+47×5.7
=(43+57)×4.7
=100×4.7
=470
原因:47缩小10倍,5.7就应该扩大10倍。

43×4.7+47×5.7 =(43÷10)×(4.7×10)+47×5.7 =4.3×47+47×5.7 =(4.3+5.7)×47 =10×47 =470