Вычислите: 5/4 · 8; 9/2 · 7; 3/20 · 5; 17/4 · 12; 13/5 · 13.

1. \(\frac{5}{4}\cdot 8=10\).
2. \(\frac{9}{2}\cdot 7=\frac{63}{2}\).
3. \(\frac{3}{20}\cdot 5=\frac{15}{20}=\frac{3}{4}\).
4. \(\frac{17}{4}\cdot 12=51\).
5. \(\frac{13}{5}\cdot 13=\frac{169}{5}\).

Ответ: \(10;\ \frac{63}{2};\ \frac{3}{4};\ 51;\ \frac{169}{5}\).