\(H=\frac{3^2}{2.5}+\frac{3^2}{5.8}+\frac{3^2}{8.11}+\frac{3^2}{11.14}+...+\frac{3^2}{197.200}=3.\left(\frac{3}{2.5}+\frac{3}{5.8}+...+\frac{3}{197.200}\right)=3.\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+...+\frac{1}{197}-\frac{1}{200}\right)=3\cdot\left(\frac{1}{2}-\frac{1}{200}\right)==\frac{297}{200}\)
Tính tổng: \(B=\frac{3^2}{8.11}+\frac{3^2}{11.14}+\frac{3^2}{14.17}+...+\frac{3^2}{197.200}\)
[\(\frac{2000}{2000.2006}+\frac{2000}{2006.2012}+\frac{2000}{2012.2018}+.....+\frac{2000}{2492.2498}\)]x\(\frac{^{3^2}}{8.11}+\frac{3^2}{11.14}+\frac{3^2}{14.17}+.....+\frac{3^2}{197.200}\)
\(\frac{3^2}{2.5}+\frac{3^2}{5.8}+\frac{3^2}{8.11}+\frac{3^2}{11.14}+\frac{3^2}{14.172}\)
\(\frac{3^2}{8.11}\) +\(\frac{3^2}{11.14}\)+\(\frac{3^2}{14.17}\)+...+\(\frac{3^2}{197.200}\)
Tính
A= \(\frac{3^2}{8.11}\)+ \(\frac{3^2}{11.14}\)+ \(\frac{3^2}{14.17}\)+........+ \(\frac{3^2}{197.200}\)
Các bạn giải ra giùm mik nha ! Thanks
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
Tính : \(\frac{3}{2.5}+\frac{3}{5.8}+\frac{3}{8.11}+\frac{3}{11.14}+\frac{3}{14.17}\)
Tính : \(A=\frac{3}{5.8}+\frac{3}{8.11}+\frac{3}{11.14}+...+\frac{3}{2009.2012}+\frac{3}{2012.2015}\)
Tính:
A=1+2-3-4+5+6-7-8-+9+.....................-2012+2013+2014
B=\(\frac{2}{5.8}+\frac{2}{8.11}+\frac{2}{11.14}+...........+\frac{2}{95.85}\)
