19+19+19+19+19+19+19+20简便方法计算
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:2024/08/03 20:05:49
19+19+19+19+19+19+19+20简便方法计算
![19+19+19+19+19+19+19+20简便方法计算](/uploads/image/z/1580766-6-6.jpg?t=19%2B19%2B19%2B19%2B19%2B19%2B19%2B20%E7%AE%80%E4%BE%BF%E6%96%B9%E6%B3%95%E8%AE%A1%E7%AE%97)
19+19+19+19+19+19+19+20
=(20-1)+(20-1)+(20-1)+(20-1)+(20-1)+(20-1)+(20-1)+20
=20-1+20-1+20-1+20-1+20-1+20-1+20-1+20
=20×8-1×7
=160-7
=153
请点击下面的【选为满意回答】按钮.
=(20-1)+(20-1)+(20-1)+(20-1)+(20-1)+(20-1)+(20-1)+20
=20-1+20-1+20-1+20-1+20-1+20-1+20-1+20
=20×8-1×7
=160-7
=153
请点击下面的【选为满意回答】按钮.