Question

What is the 13th term in the arithmetic sequence described by this explicit formula an=84+(n-1)(-6)

Answer 1

Just replace n with 13 in the formula:  an=84+(n-1)(-6)

Thus, a(13)=84+(13-1)(-6) = 84 - 72 = 12 (answer)

Answer 2

Answer:

12

Step-by-step explanation:

The formula given is $a_n=84+(n-1)(-6)$

Where $a_n$ gives the nth term

Since we want 13th term, we can say we want $a_{13}$ and we plug in 13 in $n$ into the formula. So we get:

$a_n=84+(n-1)(-6)\\a_{13}=84+(13-1)(-6)\\a_{13}=84+(12)(-6)\\a_{13}=84-72\\a_{13}=12$

So, the 13th term of the sequence is 12