To model the decay of a radioactive substance, we use the formula:
\[ f(x) = A \cdot (1 - r)^x \]
where:
- \( A \) is the initial amount,
- \( r \) is the decay rate (as a decimal),
- \( x \) is the number of years.
Given that the initial amount is 600 grams and the decay rate is 6% (or 0.06 as a decimal), we can substitute these values into the formula:
- Initial amount \( A = 600 \)
- Decay rate \( r = 0.06 \)
- Therefore, \( (1 - r) = (1 - 0.06) = 0.94 \)
Now, we can express the exponential decay function as:
\[ f(x) = 600 \cdot (0.94)^x \]
Thus, the correct option that models the decay is:
f(x) = 600(0.94)^x