South Australia contains 324 separate Protected Areas with a total land area of 21,630,995 hectares(21.97% of the state’s area). 18 of these are National parks, totalling 4,337,430 hectares (4.41% of the state’s area).
... left side is now a perfect square; it is the square of (x + b/(2a)). The right side can be written as a single fraction; the common denominator is 4a2. ...