\(5S=1+\frac{2}{5}+\frac{3}{5^2}+...+\frac{2015}{5^{2014}}\Rightarrow4S=1+\frac{1}{5}+\frac{1}{5^2}+...+\frac{1}{5^{2014}}-\frac{2015}{5^{2015}}\)
Đặt B = \(1+\frac{1}{5}+\frac{1}{5^2}+...+\frac{1}{5^{2014}}\)
=> 5B = \(5+1+\frac{1}{5}+\frac{1}{5^2}+...+\frac{1}{5^{2013}}\)
=> 4B = \(5-\frac{1}{5^{2014}}
1/51+1/52+1/53+...1/99+1/100 hay so sanh voi 1/2
so sanh tong s=1/2+2/2^2+......+2015/2^2015 voi 2
Cho tong T=2/2^1+3/2^2+4/2^3 +...+2016/2^2015+2017/2^2016.So sanh T voi 3
cho A=\(\frac{1}{1+3}+\frac{1}{1+3+5}+...+\frac{1}{1+3+5+...+4031}\).so sanh A voi \(\frac{2015}{2016}\)
cho S=1\3+1\5+1\18+1\30+1\45+1\60+...+1\1485 so sanh S voi 3\5
1 phần 1*2*3 +1 phần 2*3*4+.......+1 phan 2014*2015*2016.so sanh voi 1
AI GIAI DUOC MINH TICK CHO
Cho S=1+3^2+3^4+3^6+.......+3^98+3^100.
So sanh 8S+1 voi 2^152
Tim so du cua S khi chia cho 10.
Cho tong T=2/2^1+3/2^2+4/2^3 +...+2016/2^2015+2017/2^2016.So sanh T voi 3
ai trả lời được mình tik 3 nick luôn
1+2+2^2+2^3+......+2^98. hay so sanh S voi 5*2^98
giup voiiiii dang hoc online!!!!!!
