Final answer:
The formula for the nth term of the given sequence 7, 14, 21 is a_n = 7 * 2^(n - 1).
Step-by-step explanation:
The given sequence is 7, 14, 21.
We can see that each term is obtained by multiplying the previous term by 2.
Therefore, the formula for the nth term of the sequence is: a_n = 7 * 2(n - 1)
For example, if we want to find the 5th term, we substitute n = 5 into the formula:
a5 = 7 * 2(5 - 1)
= 7 * 24
= 7 * 16
= 112