S= -(1/7^0 + 1/7^1+ 1/7^2 + 1/7^3 +...+ 1/7^2016)
Xét A = 1/7^0 + 1/7^1 + 1/7^2 + 1/7^3 +...+ 1/7^2016
=>7A= 7 + 1/7^0 + 1/7^1 + ...+ 1/7^2015
=> 6A = 7 - 1/7^2016
=> A = (7 - 1/7^2016)/6
=>S=-(7-1/7^2016)/6
Tính tổng: \(S=\left(\frac{1}{7}\right)^0+\left(\frac{1}{7}\right)^1+\left(\frac{1}{7}\right)^2+...+\left(\frac{1}{7}\right)^{2014}\)
tính tổng \(S=\left(-\frac{1}{7}\right)^0+\left(-\frac{1}{7}\right)^1+\left(-\frac{1}{7}\right)^3+\left(-\frac{1}{7}\right)^4+.....+\left(-\frac{1}{7}\right)^{2007}\)
Tính \(S=\left(-\frac{1}{7}\right)^0+\left(-\frac{1}{7}\right)^1+\left(-\frac{1}{7}\right)^2+...\left(-\frac{1}{7}\right)^{2007}\)
các bạn giúp mình với !!!
tính:\(S=\left(-\frac{1}{7}\right)^0+\left(-\frac{1}{7}\right)^1+...+\left(-\frac{1}{7}\right)^{2007}\)
Tính hợp lý nếu có thể:
a) \(2\frac{1}{7}:\left(\frac{1}{15}-1\frac{2}{5}\right)-2\frac{1}{7}:\left(\frac{17}{15}+2\frac{1}{5}\right)\)
b) \(\left(\frac{-2}{3}\right)^{-4}.\left(-4\right)^2-\left[\left(\frac{7}{3}\right)^0\right]^{2016}-10\frac{1}{3}\)
1.Tính tổng :
S = \(\left(\frac{-1}{7}\right)^o+\left(\frac{-1}{7}\right)^1+\left(\frac{-1}{7}\right)^2+...+\left(\frac{-1}{7}\right)^{2017}\)
a) Tính tổng: \(S=\left(\frac{-1}{7}\right)^0+\left(\frac{-1}{7}\right)^1+\left(\frac{-1}{7}\right)^2+...+\left(\frac{-1}{7}\right)^{2007}\)
b) Chứng minh rằng : \(\frac{1}{2!}+\frac{2}{3!}+\frac{3}{4!}+...+\frac{99}{100!}
tính S=\(\left(\frac{-1}{7}\right)^0+\left(-\frac{1}{7}\right)^1+...+\left(-\frac{1}{7}\right)^{2007}\)
Bài 1 Thưc hiện phép tính ( tính nhanh nếu có thể)
a)\(\frac{-1}{24}-\left[\frac{1}{4}-\left(\frac{1}{2}-\frac{7}{8}\right)\right]\)
b)\(\left(\frac{5}{7}-\frac{7}{5}\right)-\left[\frac{1}{2}-\left(\frac{-2}{7}-\frac{1}{10}\right)\right]\)
C)\(\left(\frac{-1}{2}\right)-\left(\frac{-3}{5}\right)+\left(\frac{-1}{9}\right)+\frac{1}{17}-\left(\frac{-2}{7}\right)+\frac{4}{35}-\frac{7}{18}\)
d)\(\left(3-\frac{1}{4}+\frac{2}{3}\right)-\left(5-\frac{1}{3}-\frac{6}{5}\right)-\left(6-\frac{7}{4}+\frac{3}{2}\right)\)
