2^n+5-4×2^n÷4×2^n+3分解因式

Sn=n(n+2)(n+4)的分项等于1/6[n(n+2)(n+4)(n+5)-(n-1)n(n+2)(n+4)]吗? 数学,简单,分多.(n^2-3n+1)-(4n^2+n-5)=? n+(n+1)+(n+2)+(n+3)+(n+4)=5n+10这道题怎么解 1/[n(n+1)]+1/[(n+1)(n+2)]+1/[(n+2)(n+3)]+1/[(n+3)(n+4)]+[(n+4)(n+5)}怎么算谢谢了, 1+(n+2)+(2n+3)+(3n+4)+(4n+5)+……((n-1)n+n)的答案 如果正整数n使得［n/2]+[n/3]+[n/4]+[n/5]+[n/6]=69,则n= 如果正整数n使得［n/2]+[n/3]+[n/4]+[n/5]+[n/6]=69,则n= -(a^2n)^5 n·n^4-n^2·n^3上课没咋听懂n·n^4-n^2·n^3 lim(n+3)(4-n)/(n-1)(3-2n) lim(n^3+n)/(n^4-3n^2+1) 求最小值 ((n+2)(n+4))/(n(n+3)) (n-3)(n-2)(n-4)等于120 求n 已知m,n为正整数,求出满足等式3n+4n+5n+…+（n+2）n=(n+3)n的所有正整数n 如果正整数n使得[n/2]+[n/3]+[n/4]+[n/5]+[n/6]=69,则n为（ ）.（[ n ]表示不超过n的最大整数） 求limn→无穷(1+2^n+3^n+4^n+5^n)^1/n [2(m+n)^5-3(m+n)^4+(-m-n)^3]÷[2(m+n)^3] (4x^n-2x^n-1-3x^n+2)÷（-5x^n-1) [(m+n)(m-n)-(m-n)²+2n(m-n)]÷4n