Question

What is the 12
th term rule of the linear sequence 13 7 1 -5 -11​

Answer 1

-53, f(n) = -6(n-1) + 13

Explanation:

given the equation to this linear/arithmetic sequence for the nth term: f(n) = -6(n-1) + 13

f(12) = -6(12-1) + 13

f(12) = -6(11) + 13

f(12) = -66 + 13

f(12) = -53

*substitute and simplify*

______________

f(n) = f(1) + d(n-1)

given f(1) = 13, f(2) = 7, and f(3) = 1

7-13 = 1-7 = -6 = d

= f(1) + d(n-1)

f(1) = 13 so

the equation must be f(n) = 13 - 6(n-1) or -6(n-1) + 13