Math Problem Statement

Write an explicit formula for a, start subscript, n, end subscripta n ​ , the n, start superscript, th, end superscriptn th term of the sequence 25, comma, 30, comma, 35, comma, dot dot dot25,30,35,

Solution

The given sequence is:

25,30,35,25, 30, 35, \dots

Step 1: Analyze the Sequence

This sequence is an arithmetic sequence because the difference between consecutive terms is constant.

  • First term (a1a_1): 2525
  • Common difference (dd): 3025=530 - 25 = 5

Step 2: Write the Explicit Formula

The general formula for the nn-th term of an arithmetic sequence is:

an=a1+(n1)da_n = a_1 + (n-1) \cdot d

Substituting a1=25a_1 = 25 and d=5d = 5:

an=25+(n1)5a_n = 25 + (n-1) \cdot 5

Simplify the formula:

an=25+5n5a_n = 25 + 5n - 5 an=5n+20a_n = 5n + 20

Final Answer:

The explicit formula for the nn-th term is:

an=5n+20a_n = 5n + 20

Would you like me to demonstrate this formula with specific terms, or do you have any additional questions?


5 Related Questions:

  1. How do you derive the general formula for an arithmetic sequence?
  2. What is the 10th term of the sequence using the explicit formula?
  3. Can you explain the difference between explicit and recursive formulas?
  4. How do you find the sum of the first nn terms in an arithmetic sequence?
  5. What are some applications of arithmetic sequences in real-world scenarios?

Tip:

When working with sequences, always verify the common difference (for arithmetic) or ratio (for geometric) to ensure the formula fits.

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Math Problem Analysis

Mathematical Concepts

Arithmetic Sequences
Explicit Formulas
Patterns in Sequences

Formulas

General formula for the nᵗʰ term of an arithmetic sequence: aₙ = a₁ + (n-1) ⋅ d
Simplified explicit formula: aₙ = 5n + 20

Theorems

Arithmetic Sequence Formula

Suitable Grade Level

Grades 6-8