Các câu hỏi tương tự
\(1,\left(n+2\right)⋮\left(n+1\right)\)
2 ,\(8⋮\left(n-2\right)\)
3,\(\left(2n+1\right)⋮\left(6-n\right)\)
4;\(3n⋮\left(n-1\right)\)
5, \(\left(3n+5\right)⋮\left(2n+1\right)\)
6, \(\left(3n+1\right)⋮\left(2n-1\right)\)
So sánh với 3
\(\left(1+\frac{1}{2}\right)+\left(1+\frac{1}{5}\right)+\left(1+\frac{1}{9}\right)+....+\left(1+\frac{2}{n^2+3n}\right)\)
A=\(\left(1+\frac{1}{2}\right)+\left(1+\frac{1}{5}\right)+\left(1+\frac{1}{9}\right)+...+\left(1+\frac{2}{n^2+3n}\right)\)
So sánh A với 3
CMR
\(1\times2+2\times5+3\times8+...+n\left(3n-1\right)=n^2\left(n+1\right)\)
Tìm các số nguyên n thỏa mãn :
a)\(\left(n+5\right)⋮\left(n-2\right)\)
b)\(\left(2n+1\right)⋮\left(n-5\right)\)
c) \(\left(n^2+3n-13\right)⋮n+3\)
d)\(\left(n^2+3\right)⋮\left(n-1\right)\)
chứng tỏ rằng với mọi n thuộc N* ta có :
\(\frac{1}{2.5}+\frac{1}{5.8}+...+\frac{1}{\left(3n-1\right)\left(3n+2\right)}=\frac{n}{2\left(3n+2\right)}\)
Tìm n biết:
\(\left(n^2+3n+4\right)⋮\left(n+3\right)\)
Tìm \(n\in N\)để:
a/ \(\left(n+8\right)⋮n\)
b/ \(5⋮\left(n+3\right)\)
c/ \(\left(n+8\right)⋮\left(n+3\right)\)
d/ \(3n+13⋮n+2\)
e/ \(\left(5n+2\right)⋮\left(9-2n\right)\)
Chứng tỏ rằng với mọi n thuộc N* ta có :\(\frac{1}{2x5}\)+\(\frac{1}{5x8}\)+...+\(\frac{1}{\left(3n-1\right)x\left(3n+2\right)}\)=\(\frac{n}{2x\left(3n+2\right)}\)