This is negative so the first bit is 1.
Since the exponent is represented with a bias of +31, this exponent is represented by -3+ 31= 29 which is 011101 in base2. 5 is 101 in base 2 so this number would be represented by 1011101000000101. That is the way I would do it. I confess that I don't know what "a hidden bit" is.