Negating a fraction

When negating a fraction written on two lines, just putting a minus sign in front is easy to mistake for a long dividing line:

\[ - \frac{x^3 + 3x^2 - 5x +2}{25} \]

To make it clearer, you could put brackets round the fraction:

\[ - \left( \frac{x^3 + 3x^2 - 5x +2}{25} \right) \]

Or you could negate the numerator, but this introduces an opportunity to make a sign error.

\[ \frac{-x^3 - 3x^2 + 5x - 2}{25} \]