69×27-27×18 49×69的简便运算方法?

2024-11-19 08:49:40
推荐回答(2个)
回答(1):

69×27–27×18
=27×(69–18)
=27×51
=27×(50+1)
=27×50+27
=1350+27
=1377
49×69
=(50–1)×(70–1)
=3500–70–50–1
=3500–121
=3379

回答(2):

69*27-27*18
=27*(69-18)
=27(50+1)
=1350+27
=1377
49*69
=(50-1)*69
=3450-69
=3381