Final answer:
The explicit formula that defines the given arithmetic sequence -34, -44, -54, -64, and -74 is an = -34 - 10(n-1).
Step-by-step explanation:
The given arithmetic sequence, -34, -44, -54, -64, and -74, can be defined by the explicit formula an = -34 - 10(n-1), where an represents the nth term in the sequence. In this formula, the common difference between consecutive terms is -10, and the first term is -34.