Find the rth term of an A.P., the sum of whose first `n` terms is `3n^2+4n`

Explanation

To find the r-th term of an arithmetic progression (A.P.) where the sum of the first n terms is given by \( S_n = 3n^2 + 4n \), we can follow these steps:

### Step 1: Understand the relationship between the sum of terms and the r-th term
The r-th term of an A.P. can be expressed in terms of the sum of the first r terms and the sum of the first (r-1) terms:
\[ T_r = S_r - S_{r-1} \]

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