a. First five terms: 9,13,17,21,25
b. Sum of first 25 terms = 1425
c. The given sequence is an arithmetic sequence because the common difference between two consecutive terms is same.
Further explanation:
Given
Formula of sequence
<u>1. First 5 terms:</u>
For first 5 terms, we have to put n=1,2,...5,
So,
<u>2. Sum of first 25 terms:</u>
For that we have to find 25th term first
The formula for sum is:
<u>3. Type of sequence</u>
The given sequence is an arithmetic sequence because the common difference between two consecutive terms is same.
i.e.
Keywords: Arithmetic sequence, Sum of arithmetic sequence
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