如题所述
第1个回答 2021-08-04
72x79
=(70+2)x(70+9)
=4900+630+140+18
=4900+770+18
=4900+788
=5688
=(70+2)x(70+9)
=4900+630+140+18
=4900+770+18
=4900+788
=5688
第2个回答 2021-08-04
72*79
=72*(80-1)
=72*80-72
=5760-72
=5688
=72*(80-1)
=72*80-72
=5760-72
=5688
第3个回答 2021-08-05
72×79
=(70+2)×(80-1)
=5600-70+160-2
=5690-2
=5688
=(70+2)×(80-1)
=5600-70+160-2
=5690-2
=5688
第4个回答 2021-08-04
72*79
=72*(80-1)
=72*80-72*1
=5688
=72*(80-1)
=72*80-72*1
=5688
第5个回答 2021-08-05
72*79
=72*(80-1)
=72*80-72
=5760-72
=5688
=72*(80-1)
=72*80-72
=5760-72
=5688