Given the explicit formula:

a5 = 8 + 7 (n - 1)
a) What term is the formula finding?
b) What value should replace n?
The answer choices are: 7, 8, 5, and 6

1 answer

The explicit formula given is:

\[ a_n = 8 + 7(n - 1) \]

a) The formula is finding the \( n \)-th term of the sequence, so we can denote that \( a_n \) represents the \( n \)-th term of the sequence.

b) To find the specific term represented by \( a_5 \), we need to replace \( n \) with 5 in the formula.

Thus, we should replace \( n \) with 5:

\[ a_5 = 8 + 7(5 - 1) \]

Calculating this:

\[ a_5 = 8 + 7(4) = 8 + 28 = 36 \]

However, you asked for what value should replace \( n \) to identify the correct term. Looking solely at the definition of \( a_5 \), the value of \( n \) that corresponds to this term is 5.

Therefore:

  • a) The formula is finding the \( n \)-th term of the sequence.
  • b) The value that should replace \( n \) is 5.