因式分解 9.6 学与练若n^2+3n=1,求n(n+1)(n+2)+1

证明不等式：(1/n)^n+(2/n)^n+(3/n)^n+.+(n/n)^n 若n²+3n=1,求n(n+1)(n+2)+1的值. 2^n/n*(n+1) 因式分解m^2-(n+1)m+n 若n为正整数,求1/n(n+1)+1/(n+1)(n+2)＋1/(n+2)(n+3)+1/(n+3)(n+4)+.+1/ 1、若f(n)=[n²+1]-n,g(n)=n-[n²-1],h(n)=1/(2n),求f(n),g 1\n(n+3)+1\(n+3)(n+6)+1\(n+6)(n+9)=1\2 n+18 n为正整数,求n的值 求极限Xn=n/(n^2+1)+n/(n^2+2)+n/(n^2+3)+……+n/(n^2+n), 1 + (n + 1) + n*(n + 1) + n*n + (n + 1) + 1 = 2n^2 + 3n + 3 证明(1+2/n)^n>5-2/n（n属于N+,n>=3) [3n(n+1)+n(n+1)(2n+1)]/6+n(n+2)化简 若(3m-2n+1)与|5m=2n-n|互为相反数,求m+n的值