If `x=-2\ a n d\ y=1,` by using an identity find the value: `(4y^2-9x^2)(16 y^4+36 x^2y^2+81 x^4)`

Explanation

To solve the expression \((4y^2 - 9x^2)(16y^4 + 36x^2y^2 + 81x^4)\) using an algebraic identity, we can follow these steps:

### Step 1: Identify the Algebraic Identity
The expression can be recognized as a product of the form \((a - b)(a^2 + ab + b^2)\), which is equivalent to \(a^3 - b^3\).

Here, we can let:
- \(a = 4y^2\)
- \(b = 9x^2\)
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