来自李玉坤的问题
简便运算799999+79999+7999+799+79=22×43+22×32+75×18=
简便运算
799999+79999+7999+799+79=
22×43+22×32+75×18=
1回答
2020-06-26 12:27
简便运算799999+79999+7999+799+79=22×43+22×32+75×18=
简便运算
799999+79999+7999+799+79=
22×43+22×32+75×18=
799999+79999+7999+799+79
=800000-1+80000-1+8000-1+800-1+80-1
=888880-5
=888875
22×43+22×32+75×18
=22×(43+32)+75×18
=22×75+75×18
=75×(22+18)
=75×40
=3000