两道递等式计算,巧算
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/13 08:11:23
两道递等式计算,巧算
![](http://img.wesiedu.com/upload/4/c2/4c2b33aa3df54c51d048de6f40ac6d95.jpg)
![](http://img.wesiedu.com/upload/4/c2/4c2b33aa3df54c51d048de6f40ac6d95.jpg)
![两道递等式计算,巧算](/uploads/image/z/6473773-37-3.jpg?t=%E4%B8%A4%E9%81%93%E9%80%92%E7%AD%89%E5%BC%8F%E8%AE%A1%E7%AE%97%2C%E5%B7%A7%E7%AE%97%26nbsp%3B)
7.8x7.5+7.8x2.6-78
=7.8x7.5+7.8x2.6-7.8x10
=7.8x(7.5+2.6-10)
=7.8x0.1
=0.78
(6.2x6.8+1.8x6.8)x12.5
=6.8x(6.2+1.8)x12.5
=6.8x(8x12.5)
=6.8x100
=680
=7.8x7.5+7.8x2.6-7.8x10
=7.8x(7.5+2.6-10)
=7.8x0.1
=0.78
(6.2x6.8+1.8x6.8)x12.5
=6.8x(6.2+1.8)x12.5
=6.8x(8x12.5)
=6.8x100
=680