Evaluate: `intsqrt(16\ x^2+25)\ dx`

Explanation

To evaluate the integral \( \int \sqrt{16x^2 + 25} \, dx \), we can follow these steps:

### Step 1: Factor out the constant from the square root
We start by factoring out the constant from the square root:

\[ \int \sqrt{16x^2 + 25} \, dx = \int \sqrt{16(x^2 + \frac{25}{16})} \, dx \]
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