Question

71×79的速算方法？

Answer 1

71×79速算方法
71x80-79
＝5680-79
＝5601

Answer 2

快速方法：71*79=71*（80-1）
=71*80-71
=5609

Answer 3

71x（80－1）＝71x80－71＝5680－71＝5609
求采纳

Answer 4

71x79
=(70+1)(80-1)
=5600+80-70-1
=5680-71
=5609

Answer 5

71x（80－1）＝71x80－71＝5680－71＝5609。