1/1*3+1/2*4+1/3*5+.+1/18*20 简便运算
来源:学生学帮网 编辑:学帮网 时间:2024/07/07 23:11:01
1/1*3+1/2*4+1/3*5+.+1/18*20 简便运算
1/1*3+1/2*4+1/3*5+.+1/18*20
=(1-1/3+1/2-1/4+1/3-1/5+……+1/18-1/20)÷2
=(1+1/2-1/19-1/20)÷2
=531/380÷2
=531/760
1/1*3+1/2*4+1/3*5+.+1/18*20 简便运算
1/1*3+1/2*4+1/3*5+.+1/18*20
=(1-1/3+1/2-1/4+1/3-1/5+……+1/18-1/20)÷2
=(1+1/2-1/19-1/20)÷2
=531/380÷2
=531/760