cho A = 1+2+3+4+...+n va B = 2n + 1 ( voi n thuoc N , n lon hon hoac bang 2) chung minh A va B la hai so nguyen to cung nhau
Tïm n thuoc N sao cho
a) 24 : het 2n - 1(n lon hon hoac bang 1)
b) 4n - 7 : het 2n - 1 (n lon hon hoac bang 1)
So lien truoc cua so 3m -1 la so nao?( Voi m thuoc N va m lon hon hoac bang 2)
ai trl dc mik tick cho nha
1¦ viet tap A cac so N n biet :
52/13 < n < hoac = 56/7
2¦ tim n thuoc N sao cho cac phan so co gt la so Z
a. n+6 : n
b n : n-3
3¦ tim 2 phan so co hieu bang 7 biet 1/3 so nho = 1/4 so lon
nhanh nha mik dang can
CMR :\(\frac{1}{2^2}+\frac{1}{3^2}+\frac{1}{4^2}+......+\frac{1}{n^2}< 1\)
(n Thuoc N;n lon hon hoac = 2
tim n cac tich sau voi n thuoc N, n> hoac bang 2
(1-1/2)(1-1/30)(1-1/4)......(1-1/n)
(1+1/2)(1+1/3)(1+1/4)...(1+1/n)
tim x thuoc N biet
a, 125.n=5^7
b, 2^3.n-3^4=2^5-5
c, (2^3+2) n+3^2.n.5-10=10^2
d, 5^n.5=125
e, 9 be hon hoac bang 3^n<90
f, (3n+1)^3=64
tim x thuoc N biet
a, 125.n=5^7
b, 2^3.n-3^4=2^5-5
c, (2^3+2) n+3^2.n.5-10=10^2
d, 5^n.5=125
e, 9 be hon hoac bang 3^n<90
f, (3n+1)^3=64