计算(x+1)(x+2)/1+(x+2)(x+3)/1+(x+3)(x+4)/1+……+(x+2008)(x+2009)/1RT

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计算(x+1)(x+2)/1+(x+2)(x+3)/1+(x+3)(x+4)/1+……+(x+2008)(x+2009)/1RT

计算(x+1)(x+2)/1+(x+2)(x+3)/1+(x+3)(x+4)/1+……+(x+2008)(x+2009)/1RT
计算(x+1)(x+2)/1+(x+2)(x+3)/1+(x+3)(x+4)/1+……+(x+2008)(x+2009)/1
RT

计算(x+1)(x+2)/1+(x+2)(x+3)/1+(x+3)(x+4)/1+……+(x+2008)(x+2009)/1RT
拆项法,应用公式1/[n(n+1)]=1/n-1/(n+1):
原式=1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3)+...+1/(x+2008)-1/(x+2009)
=1/(x+1)-1/(x+2009)
=2008/[(x+1)(x+2009)]

=1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3)+1/(x+3)-1/(x+4)+……+1/(x+2008)-1/(x+2009)
=1/(x+1)-1/(x+2009)
=2008/(x+1)(x+2009)
你的除号写反了吧...