[tex]f(x) = ( \sqrt{x} + 2)( \sqrt{x} - 2)[/tex]

First, we can expand the equation using the distributive property:

[tex]f(x) = \sqrt{x} \cdot \sqrt{x} - 2 \cdot \sqrt{x} + 2 \cdot \sqrt{x} - 4[/tex]

Simplify this further:

[tex]f(x) = x - 4[/tex]

Therefore, the function simplifies to [tex]f(x) = x - 4[/tex].