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解方程:1/(x的平方+x)+1/(x的平方+3x+2)+1/(x的平方+5x+6)+1/(x的平方+7x+12)=4/

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/11/08 13:56:41
解方程:1/(x的平方+x)+1/(x的平方+3x+2)+1/(x的平方+5x+6)+1/(x的平方+7x+12)=4/21
化简:
(1/x)*(1/(x+1))+(1/(x+1))*(1/(x+2))+(1/(x+2))*(1/(x+3))+(1/(x+3))*(1/(x+4))=4/21
(1/x)-(1/(x+1))+(1/(x+1))-(1/(x+2))+(1/(x+2))-(1/(x+3))+(1/(x+3))-(1/(x+4))=4/21
(1/x)*(1/(x+4))=1/21
x=3