In IEEE double precision n=53. So to represent 16 I can do the following:
The next biggest number from $16=+(.10 \dots 01)_22^5=2^{-1}2^5+2^{-53}2^5=16+2^{-48}$
Now the biggest number from $-16=-16+2^{-49}$, but how to show this formally like i did above for positive $16$ case?