1-(1/(2n+1))怎样化简成n/(n+1)

1-(1/(2n+1))怎样化简成n/(n+1) 怎样证明n/(n+1) {n(n+1)(n+2)}分之一怎样求和 n*【n+1】*【n+2】化简成什么? 2^n/n*(n+1) 证明不等式：(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n 怎样把n^4+2n^3+3n^2+2n+1因式分解成n*(n+1)+1)^2? 怎样证明n*n/n+1=n-n/n+1的正确性 根号下n(n+1)(n+2)(n+3)+1 的化简怎样化简 根号下n(n+1)(n+2)(n+3)+1 （3n-2)(3n+1)(3n+4)(3n+7)+81怎样分解因式 怎样化简根号下n(n+1)(n+2)(n+3) (n+2)!/(n+1)! n为怎样的自然数时,1^n+2^n+3^n+4^n能被10整除 怎样化简2^n-2^(n-1)-2? (n+2)×(n+1)是什么?怎样化简? [3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简 [3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简 化简n分之n-1+n分之n-2+n分之n-3+.+n分之1