Answer:
f(n) = 7 - 4(x - 1)
Step-by-step explanation:
In order to find the answer, you first have to identify the formula which is f(n) = b + m(x - 1). You have to fill in m and b. In order to fill in b, you have to find the first number in the sequence which is 7. In order to find m, you have to find how much each number increases by. So, you have to see how much is added between 7 and 3, and 3 to -1 and so on. 3 -7 and -1 - 3 = -4 so, the common difference or m is -4. So, the final rule would be f(1) = 7 - 4(x - 1).
