Các câu hỏi tương tự
Tính:
A=1+2-3-4+5+6-7-8-+9+.....................-2012+2013+2014
B=\(\frac{2}{5.8}+\frac{2}{8.11}+\frac{2}{11.14}+...........+\frac{2}{95.85}\)
1) Tính nhanh:
a) A = \(\frac{3}{2}+\frac{3}{6}+\frac{3}{12}+\frac{3}{20}+....+\frac{3}{90}\)
b) B = \(\frac{2}{2.5}+\frac{2}{5.8}+\frac{2}{8.11}+\frac{2}{11.14}+\frac{2}{14.17}\)
Lưu ý: Dấu chấm là dấu nhân nha mọi người
Tìm x, biết rằng:
a)\(\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+...+\frac{1}{x\left(x+3\right)}=\frac{101}{1540}\)
b)\(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{x\left(x+1\right):2}=1\frac{1991}{1993}\)
Tìm x biết
a) \(\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+...+\frac{1}{x\left(x+3\right)}=\frac{101}{1540}\)
b) \(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x\left(x+1\right)}=1\frac{2017}{2019}\)
\(\frac{3^2}{2.5}+\frac{3^2}{5.8}+\frac{3^2}{8.11}+\frac{3^2}{11.14}+\frac{3^2}{14.172}\)
Tính:
a)\(1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{2016}}\)
b)\(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right)....\left(1-\frac{1}{20}\right)\)
c)\(\frac{9}{5.8}+\frac{9}{8.11}+\frac{9}{11.14}+\frac{9}{14.17}+...+\frac{9}{2006.2009}\)
( LÀM ĐẦY ĐỦ NHÉ MẤY PẠN! XONG RÙI MÌNH TICK CHO)
Tìm x, biết :
a, \(\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+...+\frac{1}{x.\left(x+3\right)}=\frac{101}{1540}\)
b, \(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{x.\left(x+1\right):2}=1\frac{1991}{1993}\)
Tính H=\(\frac{3^2}{1.5}+\frac{3^2}{5.8}+\frac{3^2}{8.11}+\frac{3^2}{11.14}+...+\frac{3^2}{197.200}\)
Tìm x biết
a \(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}...........+\frac{1}{2.\left(x-1\right)}=\frac{999}{1000}\)
b \(\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+.........+\frac{1}{2.\left(x+5\right)}=\frac{101}{1540}\)