Question
What is the 15th term in the arithmetic sequence described by this explicit formula?
an= 63 +(n-1)(-7)
The 15th term is
choose your answer...
an= 63 +(n-1)(-7)
The 15th term is
choose your answer...
Answers
GPT-4o mini
To find the 15th term of the arithmetic sequence described by the explicit formula \( a_n = 63 + (n - 1)(-7) \), we need to substitute \( n = 15 \) into the formula.
\[
a_{15} = 63 + (15 - 1)(-7)
\]
Calculating the expression step by step:
1. Calculate \( 15 - 1 \):
\[
15 - 1 = 14
\]
2. Now, calculate \( 14 \times -7 \):
\[
14 \times -7 = -98
\]
3. Now substitute back into the formula:
\[
a_{15} = 63 + (-98)
\]
4. Now perform the addition:
\[
a_{15} = 63 - 98 = -35
\]
Therefore, the 15th term of the sequence is \(\boxed{-35}\).
\[
a_{15} = 63 + (15 - 1)(-7)
\]
Calculating the expression step by step:
1. Calculate \( 15 - 1 \):
\[
15 - 1 = 14
\]
2. Now, calculate \( 14 \times -7 \):
\[
14 \times -7 = -98
\]
3. Now substitute back into the formula:
\[
a_{15} = 63 + (-98)
\]
4. Now perform the addition:
\[
a_{15} = 63 - 98 = -35
\]
Therefore, the 15th term of the sequence is \(\boxed{-35}\).