Các câu hỏi tương tự
a^3+3a^2+5=5^b .Biet:a+3=5^c
tính C= 2^2+5^2+8^2+...+(3n-1)^2
\(Tính:C=2^2+5^2+8^2+...+\left(3n-1\right)^2\)
cho Sn=(5/1*2*3)+(8/2*3*4)+...+[3n+2/n*(n+1)*(n+2)].CMR:S2008<2
Cho S(n)=5/1*2*3+8/2*3*4+...+3n+2/n(n+1)(n+2).CMR: S(2008)<2
Cho S(n)=5/1*2*3+8/2*3*4+...+3n+2/n(n+1)(n+2).CMR: S(2008)<2
Chứng minh rằng: \(2+5+8+...+\left(3n-1\right)=\frac{n\left(3n+1\right)}{2}\)
Cho E= 22+52+82+...+(3n-1)2
Tính E?
Chứng minh rằng: \(2+5+8+...+\left(3n-1\right)=\frac{n\left(3n+1\right)}{2}\)