Evaluate each of the following using identities:
(i)`(2x-1/x)^2`
(ii) `(2x+y)(2x-y)`

Explanation

Let's solve the given problems step by step using algebraic identities.

### Part (i): Evaluate \((2x - \frac{1}{x})^2\)

**Step 1:** Identify the identity to use.
We will use the identity for \((a - b)^2 = a^2 - 2ab + b^2\).

**Step 2:** Assign values for \(a\) and \(b\).
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