Bài làm:
\(\frac{3}{200}-\frac{3}{110}-\frac{3}{90}-\frac{3}{72}-\frac{3}{56}-...-\frac{3}{2}\)
\(=\frac{3}{200}-3\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+...+\frac{1}{110}\right)\)
\(=\frac{3}{200}-3\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{10.11}\right)\)
\(=\frac{3}{200}-3\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{10}-\frac{1}{11}\right)\)
\(=\frac{3}{200}-3\left(1-\frac{1}{11}\right)\)
\(=\frac{3}{200}-\frac{30}{11}=-\frac{5967}{2200}\)
Học tốt!!!!
We bear're bears!
:)
