Ah, I see! You're absolutely right. If the original expression was something like $6e^{3x} - 4e^{3x}$, the correct simplification would indeed leave you with:

$6e^{3x} - 4e^{3x} = 2e^{3x}$

If you're working with this in the context of derivatives, the derivative of $2e^{3x}$ would be:

$\frac{d}{dx}(2e^{3x}) = 2 \cdot 3e^{3x} = 6e^{3x}$

This is because of the chain rule, which brings down the exponent as a constant multiplier.

If there was a mistake or confusion in the steps, I hope this clears it up! Let me know if you want to go over this in more detail or have any other questions.