\(\frac{5}{2}-\frac{1}{3}+\frac{1}{4}\)
\(\frac{2}{5}-0,4+3\frac{1}{2}\)
\(\left(\frac{3}{4}-4\right):\left(\frac{1}{2}+\frac{1}{8}\right)\)
\(\frac{7}{13}:\frac{8}{17}+\frac{7}{13}\cdot\frac{5}{17}\)
\(\frac{1}{3\cdot5}+\frac{1}{5\cdot7}............+\frac{1}{91\cdot93}\)