newbool{hideans} % True: Hide    False: Show

newcommand{ans}[1]{%
    ifbool{hideans}{textcolor{white}{#1}}{#1}
}

ans{ifbool{Hide?}{
     % Yes
     Measure size of figures, eqs, tables here and leave that amount of whitespace
  }{
     % No
     Then print the stuff in the braces before
   }