Watson Ellis
02/27/2024 · Elementary School
Find the 78 th term of the arithmetic sequence \( 14,5,-4, \ldots \)
UpStudy ThothAI Solution
Tutor-Verified Answer
Step-by-step Solution
To find the 78th term of the arithmetic sequence given by \( 14, 5, -4, \ldots \), we first need to identify the first term and the common difference of the sequence.
The first term \( a \) is:
\[
a = 14
\]
Next, we calculate the common difference \( d \) by subtracting the first term from the second term:
\[
d = 5 - 14 = -9
\]
Now that we have the first term \( a = 14 \) and the common difference \( d = -9 \), we can use the formula for the \( n \)-th term of an arithmetic sequence, which is given by:
\[
a_n = a + (n-1)d
\]
To find the 78th term (\( n = 78 \)):
\[
a_{78} = 14 + (78 - 1)(-9)
\]
\[
= 14 + 77 \cdot (-9)
\]
\[
= 14 - 693
\]
\[
= 14 - 693 = -679
\]
Thus, the 78th term of the arithmetic sequence is:
\[
\boxed{-679}
\]
Quick Answer
The 78th term of the sequence is -679.
Answered by UpStudy AI and reviewed by a Professional Tutor
UpStudy ThothAI
Self-Developed and Ever-Improving
Thoth AI product is constantly being upgraded and optimized.
Covers All Major Subjects
Capable of handling homework in math, chemistry, biology, physics, and more.
Instant and Accurate
Provides immediate and precise solutions and guidance.
Try Now
Ask Tutors
Ask AI
10x
Fastest way to Get Answers & Solutions
By text
Enter your question here…
By image
Re-Upload
Submit