To simplify the expression \( x^2 - 497x - x^2 \), we can first combine like terms.
The \( x^2 \) terms cancel each other out:
\[ x^2 - 497x - x^2 = -497x \]
Now we can see that the expression can be simplified to \( -497x \).
This means none of the options provided are correct, as we only have \( -497x \) in its simplest form.
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