Final answer:
The correct formula to find the nth term of the sequence 54, 50, 46, 42, ... is An = 54 - 4(n - 1). Using this, the 20th term is calculated to be -22.
Step-by-step explanation:
To find the 20th term of the sequence 54, 50, 46, 42, ..., we must first determine the correct formula for the nth term (also represented as An). When examining the sequence, we can see that it is an arithmetic sequence with a common difference of -4 (since each term is 4 less than the previous term).
The first term of the sequence is 54. Therefore, the formula should start from that value, and considering the common difference of -4 for each subsequent term, the correct formula would be:
An = 54 - 4(n - 1)
Now using this formula, to find the 20th term, we plug in n=20:
A20 = 54 - 4(20 - 1) = 54 - 4(19) = 54 - 76 = -22
Thus, the 20th term of the sequence is -22.