To construct an exponential equation that models the number of words \( y \) the AI can learn after \( x \) hours, we start with the following information:
- The AI initially knows 125 words.
- The AI's vocabulary doubles every 8 hours.
When modeling exponential growth, we use the formula:
\[ y = y_0 \cdot a^{(t/T)} \]
where:
- \( y_0 \) is the initial value (125 words),
- \( a \) is the growth factor (2, since the vocabulary doubles),
- \( t \) is the time elapsed,
- \( T \) is the duration in which the growth factor applies (8 hours in this case).
Substituting the values into the equation, we have:
\[ y = 125 \cdot 2^{(x/8)} \]
However, none of the provided options exactly match this equation.
Let's analyze the answer choices based on the given conditions and see if any of them can be interpreted to match our equation.
- \( y = 8 \cdot (2.5)^x \)
- \( y = 2 \cdot (2.5)^x \)
- \( y = 2.5 \cdot (8)^x \)
- \( y = 2 \cdot (2)^x \)
None of these options represent the correct model based on the specified conditions, as they all have different growth factors or scales.
To summarize, we determined that \( y = 125 \cdot 2^{(x/8)} \) is the correct model based on the doubling growth. Unfortunately, none of the provided options match this equation correctly. Therefore, none of the options are correct.