解方程:1/x(x-1)+1/x(x+1)+1/(x+1)(x+2)+…+1/(x+9)(x+10)=1/12

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/16 19:24:33

解方程:1/x(x-1)+1/x(x+1)+1/(x+1)(x+2)+…+1/(x+9)(x+10)=1/12
解方程:1/x(x-1)+1/x(x+1)+1/(x+1)(x+2)+…+1/(x+9)(x+10)=1/12

解方程:1/x(x-1)+1/x(x+1)+1/(x+1)(x+2)+…+1/(x+9)(x+10)=1/12
1/x(x-1)+1/x(x+1)+1/(x+1)(x+2)+…+1/(x+9)(x+10)
=1/(x-1)-1/x+1/x-1/(x+1)+1/(x+1)-1/(x-2)+.+1/(x+9)-1/(x+10)
=1/(x-1)-1/(x+10)
=11/(x-1)(x+10)=1/12
x^2+9x-142=0
(x+9/2)^2=649/4
x=(-9±√649)/2

1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)+……+1/(x+9)(x+10)=1/x-1/(x+1)+1/(x+1)-1/(x+2)+……+1/(x+9)-1/(x+10)=1/x-1/(x+10)=10/(x²+x)