Open in App
Log In Start studying!

Select your language

Suggested languages for you:

Problem 660

Given that the first term of an arithmetic sequence is 56 and the seventeenth term is 32 , find the tenth term and the twenty - fifth term.

Short Answer

Expert verified
The tenth term of the arithmetic sequence is \(\dfrac{85}{2}\), and the twenty-fifth term is 20.
See the step by step solution

Step by step solution

Unlock all solutions

Get unlimited access to millions of textbook solutions with Vaia Premium

Over 22 million students worldwide already upgrade their learning with Vaia!

Step 1: Define the arithmetic sequence formula

The formula for the nth term of an arithmetic sequence is given by: \(a_n = a_1 + (n - 1)d\) where \(a_n\) is the nth term, \(a_1\) is the first term, \(n\) is the term number, and \(d\) is the common difference between consecutive terms.

Step 2: Calculate the common difference

We are given the first term (\(a_1 = 56\)) and the seventeenth term (\(a_{17} = 32\)). We can use the arithmetic sequence formula to find the common difference (d): \(a_{17} = a_1 + (17 - 1)d\) Substitute the given values into the formula: \(32 = 56 + (16)d\) Now, we solve for d: \(16d = 32 - 56\) \(16d = -24\) \(d = -\dfrac{24}{16} = -\dfrac{3}{2}\) The common difference, d, is \(-\dfrac{3}{2}\)

Step 3: Find the tenth term

Now that we have the common difference, we can find the tenth term, \(a_{10}\), using the arithmetic sequence formula: \(a_{10} = a_1 + (10 - 1)d\) Substitute the values: \(a_{10} = 56 + (9)(-\dfrac{3}{2})\) \(a_{10} = 56 - \dfrac{27}{2}\) \(a_{10} = \dfrac{85}{2}\) The tenth term, \(a_{10}\), is \(\dfrac{85}{2}\).

Step 4: Find the twenty-fifth term

Similarly, we can find the twenty-fifth term, \(a_{25}\), using the arithmetic sequence formula: \(a_{25} = a_1 + (25 - 1)d\) Substitute the values: \(a_{25} = 56 + (24)(-\dfrac{3}{2})\) \(a_{25} = 56 - 36\) \(a_{25} = 20\) The twenty-fifth term, \(a_{25}\), is 20. To summarize, the tenth term of the arithmetic sequence is \(\dfrac{85}{2}\), and the twenty-fifth term is 20.

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Access millions of textbook solutions in one place

  • Access over 3 million high quality textbook solutions
  • Access our popular flashcard, quiz, mock-exam and notes features
  • Access our smart AI features to upgrade your learning
Get Vaia Premium now
Access millions of textbook solutions in one place

Join over 22 million students in learning with our Vaia App

The first learning app that truly has everything you need to ace your exams in one place.

  • Flashcards & Quizzes
  • AI Study Assistant
  • Smart Note-Taking
  • Mock-Exams
  • Study Planner
Join over 22 million students in learning with our Vaia App Join over 22 million students in learning with our Vaia App

Recommended explanations on Math Textbooks