1.1\2-[-(+1\6)-(+1\12)]+[-(-1\20)+1\30]-[(-1\42)+1\56]本人只知道这么写:=1×1\2+1\2×1\3+1\3×1\4+1\4×1\5+1\5×1\6-1\7×1\8 2.在1、2、3、……、50前添加“+”或“-”,并求它们的和,所得结果的最小非负数是多少?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/06 13:59:40
![1.1\2-[-(+1\6)-(+1\12)]+[-(-1\20)+1\30]-[(-1\42)+1\56]本人只知道这么写:=1×1\2+1\2×1\3+1\3×1\4+1\4×1\5+1\5×1\6-1\7×1\8 2.在1、2、3、……、50前添加“+”或“-”,并求它们的和,所得结果的最小非负数是多少?](/uploads/image/z/3831587-35-7.jpg?t=1.1%5C2-%5B-%28%2B1%5C6%29-%28%2B1%5C12%29%5D%2B%5B-%28-1%5C20%29%2B1%5C30%5D-%5B%28-1%5C42%29%2B1%5C56%5D%E6%9C%AC%E4%BA%BA%E5%8F%AA%E7%9F%A5%E9%81%93%E8%BF%99%E4%B9%88%E5%86%99%EF%BC%9A%3D1%C3%971%5C2%2B1%5C2%C3%971%5C3%2B1%5C3%C3%971%5C4%2B1%5C4%C3%971%5C5%2B1%5C5%C3%971%5C6-1%5C7%C3%971%5C8+2.%E5%9C%A81%E3%80%812%E3%80%813%E3%80%81%E2%80%A6%E2%80%A6%E3%80%8150%E5%89%8D%E6%B7%BB%E5%8A%A0%E2%80%9C%2B%E2%80%9D%E6%88%96%E2%80%9C-%E2%80%9D%2C%E5%B9%B6%E6%B1%82%E5%AE%83%E4%BB%AC%E7%9A%84%E5%92%8C%2C%E6%89%80%E5%BE%97%E7%BB%93%E6%9E%9C%E7%9A%84%E6%9C%80%E5%B0%8F%E9%9D%9E%E8%B4%9F%E6%95%B0%E6%98%AF%E5%A4%9A%E5%B0%91%3F)
1.1\2-[-(+1\6)-(+1\12)]+[-(-1\20)+1\30]-[(-1\42)+1\56]本人只知道这么写:=1×1\2+1\2×1\3+1\3×1\4+1\4×1\5+1\5×1\6-1\7×1\8 2.在1、2、3、……、50前添加“+”或“-”,并求它们的和,所得结果的最小非负数是多少?
1.1\2-[-(+1\6)-(+1\12)]+[-(-1\20)+1\30]-[(-1\42)+1\56]
本人只知道这么写:
=1×1\2+1\2×1\3+1\3×1\4+1\4×1\5+1\5×1\6-1\7×1\8
2.在1、2、3、……、50前添加“+”或“-”,并求它们的和,所得结果的最小非负数是多少?请列式解答.
1.1\2-[-(+1\6)-(+1\12)]+[-(-1\20)+1\30]-[(-1\42)+1\56]本人只知道这么写:=1×1\2+1\2×1\3+1\3×1\4+1\4×1\5+1\5×1\6-1\7×1\8 2.在1、2、3、……、50前添加“+”或“-”,并求它们的和,所得结果的最小非负数是多少?
1.原式=1×1\2+1\2×1\3+1\3×1\4+1\4×1\5+1\5×1\6-1\7×1\8
=1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7-1/7+1/8
=1/2+1/2-1/7-1/7+1/8
=1-2/7+1/8
=5/7+1/8
=47/56=7/8
2.-1+2+(3-4-5+6)+(7-8-9-10)+...+(47-48-49-50)=1
绝对正确的,放心吧!如果有什么不懂的还可以问我O(∩_∩)O哈!