The greatest common factor (GCF) is the largest expression that divides two or more expressions without leaving a remainder. To find the GCF of the expressions 4xy² and 20x²y⁴, we can follow these steps:
- Factor each term:
- For 4xy²: Start by identifying the coefficients and variables.
- Coefficient: 4
 - Variables: x and y (with the exponent of y being 2)
 
 - For 20x²y⁴: Similarly, we break this down.
- Coefficient: 20
 - Variables: x (with the exponent of 2) and y (with the exponent of 4)
 
 
 - For 4xy²: Start by identifying the coefficients and variables.
 - Find the GCF of the coefficients:
- The coefficients are 4 and 20.
- Factors of 4: 1, 2, 4
 - Factors of 20: 1, 2, 4, 5, 10, 20
 
The common factors are 1, 2, and 4, so the GCF of the coefficients is 4.
 
 - The coefficients are 4 and 20.
 - Find the GCF of the variables:
- For variable x: The smallest exponent is 1 (from 4xy²), so we take x¹.
 - For variable y: The smallest exponent is 2 (from 4xy²), so we take y².
 
 
Putting it all together, the GCF of 4xy² and 20x²y⁴ is the product of the GCFs of the coefficients and variables:
GCF = 4 * x¹ * y² = 4xy²
Thus, the greatest common factor of 4xy² and 20x²y⁴ is 4xy².