如题所述
第1个回答 2022-07-07
55x59一45x4
二55x(6o一丨)一(5o一5)x4
=33oo一55一2oo十2o
二352o一255
二3256∵
二55x(6o一丨)一(5o一5)x4
=33oo一55一2oo十2o
二352o一255
二3256∵
第2个回答 2022-07-08
55x59一45x5
=(45+10)x59一45x5
=45x59+10x59一45x5
=45x(59一5)+590
=45x54+590
=45ⅹ(55一1)+590
=45x55一45+590
=(50一5)(50+5)+545
=50^2一5^2+545
=2500一25+545
=3020。
=(45+10)x59一45x5
=45x59+10x59一45x5
=45x(59一5)+590
=45x54+590
=45ⅹ(55一1)+590
=45x55一45+590
=(50一5)(50+5)+545
=50^2一5^2+545
=2500一25+545
=3020。