(-2/5)n²+21n≤0

解方程(2n+1)(n+1)n-(2n-21)(n-10)(n-11)=2(2n-9)(n-4)(n-5)解方程(2n+1)(n+1)n-(2n-21)(n-10)(n-11)=2(2n-9)(n-4

已知n＾2-n-1=0,则n^3-n^2-n+5=已知n＾2-n-1=0,则n^3-n^2-n+5= 已知n＾2-n-1=0,则n^3-n^2-n+5=n³-n²-n+5

6n^2-5n-338=0n等于?6n^2-5n-338=0n等于?6n^2-5n-338=0n等于?利用求根公式,可以得x=[5-根号（8137）]/12,或[5+根号（8137）]/12不是整数

下列几组力中,合力不可能等于0的是A.3N4N6NB.1N2N4NC.2N4N6ND.5N5N1N下列几组力中,合力不可能等于0的是A.3N4N6NB.1N2N4NC.2N4N6ND.5N5N1N下列

n是自然数,0≤n≤101,则|n-1|+|n-2|+|n-3|+…+|n-100|的最小值,n是自然数,0≤n≤101,则|n-1|+|n-2|+|n-3|+…+|n-100|的最小值,n是自然数,

急1)C(n,0)+2C(n,1)+3C(n,2)+4C(n,3)+...+(n+1)C(n,n)=(n+2)*2^(n-1)2)C(n,0)+3C(n,1)+5C(n,2)+...+(2n+1)C(

有关二项式定理的证明问题.证明:2^n>n^2+n+1(n>=5,n∈N*)书上是这样证的2^n=(1+1)^n第一步=C(n,0)+C(n,1)+C(n,2)+...+c(n-1,n)+C(n,n)

已知n^2-n-1=0,则n^3-n^2+5=?已知n^2-n-1=0,则n^3-n^2+5=?已知n^2-n-1=0,则n^3-n^2+5=?n^2-n-1=0n²-n=1n^3-n^2+

n^4-6n^3-5n^2+2n=0有几个正整数解?n^4-6n^3-5n^2+2n=0有几个正整数解?n^4-6n^3-5n^2+2n=0有几个正整数解?我来试试吧...希望LZ能给点分n^4-6n

llim(n趋于无穷大)(5n^2+3n)/6n^3=0对不llim(n趋于无穷大)(5n^2+3n)/6n^3=0对不llim(n趋于无穷大)(5n^2+3n)/6n^3=0对不当然对

2^n*3^n*5^n+2/30^n2^n*3^n*5^n+2/30^n2^n*3^n*5^n+2/30^n=2^n×3^n×5^n×5²/(2×3×5)^n=2^n×3^n×5^n×5&#

3(n-1)(n+3)-2(n-5)(n-2)3(n-1)(n+3)-2(n-5)(n-2)3(n-1)(n+3)-2(n-5)(n-2)3(n-1)(n+3)-2(n-5)(n-2)=3(n^2+2

2^n*3^n*5^(n+1)/30^n2^n*3^n*5^(n+1)/30^n2^n*3^n*5^(n+1)/30^n2^n*3^n*5^(n+1)/30^n=2^n*3^n*5^n*5/(2*3*

高数题：n趋近于0,lim｛1/（n^2+n+1)+2/(n^2+n+2)+3/(n^2+n+3)+.+n/(n^2+n+n)｝=?高数题：n趋近于0,lim｛1/（n^2+n+1)+2/(n^2+n

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?Sn=n(n+2)(n+4)的分项等于1/6[n(n+2)(n+4)(n+5)-(

已知对任意的x>0恒有alnx≤b(x-1)成立,证明ln(n!)>2n-4√n,(n∈N,n≥2)其中n!=n×(n-1)×(n-2)×...×2×1已知对任意的x>0恒有alnx≤b(x-1)成立

下列公点力的合力可能为0的是()A16N5N6NB3N4N5NC3N7N11ND11N2N14N下列公点力的合力可能为0的是()A16N5N6NB3N4N5NC3N7N11ND11N2N14N下列公点

(n+1)(n+2)...(2n)n(n-1)(n-2).21逆序数(n+1)(n+2)...(2n)n(n-1)(n-2).21逆序数(n+1)(n+2)...(2n)n(n-1)(n-2).21逆

(n+1)(n+2)...2n...n(n-1)(n-2).21逆序数(n+1)(n+2)...2n...n(n-1)(n-2).21逆序数(n+1)(n+2)...2n...n(n-1)(n-2).

已知n^2-n+1=0,则n^3-n^2+n+5的值是已知n^2-n+1=0,则n^3-n^2+n+5的值是已知n^2-n+1=0,则n^3-n^2+n+5的值是n^3-n^2+n+5=n(n^2-n