Bài 1: Ta có: \(\left\{\begin{matrix}
\frac{1}{2.3}=\frac{1}{6}\\
\frac{1}{2}-\frac{1}{3}=\frac{1}{6}
\end{matrix}\right.
\Rightarrow \frac{1}{2.3}=\frac{1}{2}-\frac{1}{3}\)
\(\left\{\begin{matrix}
\frac{1}{3.4}=\frac{1}{12}\\
\frac{1}{3}-\frac{1}{4}=\frac{1}{12}
\end{matrix}\right.
\Rightarrow \frac{1}{3.4}=\frac{1}{3}-\frac{1}{4}\)
Bài 2: \(\left\{\begin{matrix}
\frac{3}{2.5}=\frac{3}{10}\\
\frac{1}{2}-\frac{1}{5}=\frac{3}{10}
\end{matrix}\right.
\Rightarrow \frac{3}{2.5}=\frac{1}{2}-\frac{1}{5}\)
\(\left\{\begin{matrix}
\frac{3}{5.8}=\frac{3}{40}\\
\frac{1}{5}-\frac{1}{8}=\frac{3}{50}
\end{matrix}\right.
\Rightarrow \frac{3}{5.8}=\frac{1}{5}-\frac{1}{8}\)
Bài 3: \(\frac{4}{1.5}=\frac{1}{1}-\frac{1}{5}\)
\(\frac{5}{2.7}=\frac{1}{2}-\frac{1}{7}\)