问题标题:
一道数学化简题.(n+1)a2n+1—nan2+anan+1=0(n属于正整数)怎么化简成(an+1+an)[(n+1)an+1—nan]a2n+1是指第N+1项的平方an2是指第N项的平方an+1是指第N+1项anan+1是指第N项与第N+1项的积.
问题描述:

一道数学化简题.

(n+1)a2n+1—nan2+anan+1=0(n属于正整数)怎么化简成(an+1+an)[(n+1)an+1—nan]

a2n+1是指第N+1项的平方

an2是指第N项的平方

an+1是指第N+1项

anan+1是指第N项与第N+1项的积.

蔡增玉回答:
  原式=n*(an+1)^2+(an+1)^2-n(an)^2+an*an+1   =n[(an+1)^2-(an)^2]+(an+1)^2+an*an+1   =n[(an+1)+(an)][(an+1)-(an)]+(an+1)[(an+1)+(an)](前面平方差公式,后面合并同类项)   =[(an+1)+(an)][n*(an+1)+(an+1)-n(an)](提取公因式)   =[(an+1)+(an)][(n+1)*(an+1)-n(an)](再合并同类项)
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