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(3x - 8)(3x+8)

\(a^2 - b^2 = (a - b)(a + b)\).

By Law of indices, \(9x^2 = 3^2 x^2 = (3x)^2\), and \(64 = 8^2\).

We use the formula and substitute a = 3x, b = 8.

\(9x^2 - 64 = (3x)^2 - 8^2 = (3x - 8)(3x +8)\)