11.25n^2+5033.75n-199500000=0 我想知道n是多少

11.25n^2+5033.75n-199500000=0 我想知道n是多少 2^n/n*(n+1) 证明不等式：(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n 7n+19/2n+1为整数,则n=?(7n+19)/(2n+1)，n≠0 (n+2)!/(n+1)! 高数求极限 2^n*n!(/n^n) n趋于无穷?高数求极限 2^n*n!/(n^n) n趋于无穷 n n n n [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 化简n分之n-1+n分之n-2+n分之n-3+.+n分之1 f(x)=e^x-x 求证(1/n)^n+(2/n)^n+...+(n/n)^n -2n+n^2+n^3还能化简吗? m-n+2n^2/(m+n) -n^3+8n^2-16n