Xét tử số:
\(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{97}+\frac{1}{99}=\left(1+\frac{1}{99}\right)+\left(\frac{1}{3}+\frac{1}{97}\right)+...+\left(\frac{1}{49}+\frac{1}{51}\right)\)
\(=\frac{100}{1.99}+\frac{100}{3.97}+...+\frac{10}{49.51}\)
\(=\frac{100}{\frac{1}{1.99}+\frac{1}{3.97}+...+\frac{1}{49.51}}\)
Vậy
\(\frac{1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{97}+\frac{1}{99}}{\frac{1}{1.99}+\frac{1}{3.97}+...+\frac{1}{49.51}}\)
\(=\frac{100}{\frac{\frac{1}{1.99}+\frac{1}{3.97}+...+\frac{1}{49.51}}{\frac{1}{1.99}+\frac{1}{3.97}+...+\frac{1}{49.51}}}=100\)