分式$\frac{4xy^{2}}{20x^{2}y}$中分子、分母的公因式为________.---**Question Stem:**
分式 $\frac{4xy^2}{20x^2y}$ 中分子、分母的公因式为_______.
**Mathematical Expression:**
Fraction: $\frac{4xy^2}{20x^2y}$
Numerator: $4xy^2$
Denominator: $20x^2y$
**Other Relevant Text:**
The question asks for the common factor of the numerator and denominator.