\[ \text{CH}_3\text{COONa} \longrightarrow \cdot \text{CH}_3 \]
\[ \text{C}_2\text{H}_5\text{COONa} \longrightarrow \cdot \text{C}_2\text{H}_5 \]
\[ 2 \cdot \text{C}_2\text{H}_5 \longrightarrow \text{CH}_3 - \text{CH}_2 - \text{CH}_2 - \text{CH}_3 \]
\[ 2 \cdot \text{CH}_3 \longrightarrow \text{CH}_3 - \text{CH}_3 \]
\[ \cdot \text{CH}_3 + \cdot \text{C}_2\text{H}_5 \longrightarrow \text{CH}_3 - \text{CH}_2 - \text{CH}_3 \]
Complete the following reactions by writing the structure of the main products:
Let one focus of the hyperbola $ \frac{x^2}{a^2} - \frac{y^2}{b^2} = 1 $ be at $ (\sqrt{10}, 0) $, and the corresponding directrix be $ x = \frac{\sqrt{10}}{2} $. If $ e $ and $ l $ are the eccentricity and the latus rectum respectively, then $ 9(e^2 + l) $ is equal to:
The largest $ n \in \mathbb{N} $ such that $ 3^n $ divides 50! is: