This step is wrong - you seem to have put a minus sign at the front for absolutely no reason...???
(I see at the same stage you've also swapped around the order of (x-2) and (x+2) in the denominator - this, however, does not force a minus sign to appear!)
Also, the 2(x+2)(x-2) in the last two lines should be x(x+2)(x-2).
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