Evaluate the following limits :
`lim_(x rarr 1) (3x + 1) (x+ 1)`

Explanation

To evaluate the limit \( \lim_{x \to 1} (3x + 1)(x + 1) \), we will follow these steps:

### Step 1: Substitute the value of \( x \)
We start by substituting \( x = 1 \) directly into the expression \( (3x + 1)(x + 1) \).

\[ (3(1) + 1)(1 + 1) \]
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