Does flipping the negative in a fraction flip all terms both sides? This is an expression that contains a negative in the denominator. If I were to take the negative and place it in the numerator, would this change all positive terms to negative and vice-versa?
Negative in denominator: 
$\frac{a+3-y^2}{-2}$
After flipping negative to the numerator: $\frac{-a-3+y^2}{2}$ (Is this correct?)

This is not an equation. Rather, this is an expression. For the change, multiply both the numerator and the denominator by -1.
