Các câu hỏi tương tự
1. Tính tổng sau: \(\frac{1}{6}+\frac{1}{24}+\frac{1}{60}+...+\frac{1}{990}\)
\(\text{Tính : }\)
\(B=2-4-6+8+10-12-14+16+...+2010-2012-2014+2016\)
\(C=\frac{1}{6}+\frac{1}{24}+\frac{1}{60}+...+\frac{1}{990}\)
Tính nhanh: \(A=\frac{1}{6}+\frac{1}{24}+\frac{1}{60}+...+\frac{1}{6840}\)
Tính :
M = \(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+...+\frac{1}{4970}\)
N = \(\frac{1}{18}+\frac{1}{54}+\frac{1}{108}+...+\frac{1}{990}\)
P = \(\frac{1}{90}-\frac{1}{72}-\frac{1}{56}-...-\frac{1}{6}-\frac{1}{2}\)
Tính:
a) A= \(\left(\frac{-2}{3}+1\frac{1}{4}-\frac{1}{6}\right).\frac{-12}{5}\)
b) B= \(\frac{13}{25}.0,25.3+\left(\frac{8}{15}-1\frac{19}{60}\right):1\frac{23}{24}\)
a) Tính tổng \(S=\frac{1}{1.2.3}+\frac{1}{2.3.4}+...+\frac{1}{98.99.100}\)
b) Chứng minh: \(A=\frac{1}{2}+\left(\frac{1}{6}+\frac{1}{24}+\frac{1}{60}+...+\frac{1}{9240}\right)>\frac{57}{462}\)
Chứng minh rằng: \(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}+\frac{1}{6}+.........-\frac{1}{1996}=\frac{1}{996}+\frac{1}{997}+....+\frac{1}{990}\)
Tờ inh tinh sắc tính:
a) A= \(\left(\frac{-2}{3}+1\frac{1}{4}-\frac{1}{6}\right).\frac{-12}{5}\)
b) B= \(\frac{13}{15}.0,25.3+\left(\frac{8}{15}-1\frac{19}{60}\right):1\frac{23}{24}\)
tính:
\(\frac{1}{18}+\frac{1}{54}+\frac{1}{108}+...+\frac{1}{990}\)