How does $-(s^2 + 4) - (2s^2) = (s^2 - 4)$? I have tried different methods to get the result. However, I cannot figure it out.
This is taken out of uni notes in a Laplace Transform question.
Thank you in advance.
P.S: Could be something pretty simple but it seems to be slipping my mind.
What you have is:
$$-\frac{(s^2+4)-(2s^2)}{(s^2+4)^2}=\frac{-(s^2+4)+(2s^2)}{(s^2+4)^2}=\frac{-s^2-4+2s^2}{(s^2+4)^2}=\frac{s^2-4}{(s^2+4)^2}$$