Simplify the expression $$ e^{4x} \cdot e^{-2x} $$ to ______...

Question Analysis
This problem assesses the ability to simplify expressions involving the natural exponential function using the properties of exponents.

Key Concept Explanation
The property of exponents states that . This property can be used to combine exponents with the same base.

Step-by-step Solution
1. Identify the given expression: .
2. Apply the exponent multiplication rule: