Australia
Belgium
Canada
China, mainland (People's Republic of China)
Chile
Denmark
England
Estonia
Finland
France
Germany
Guatemala
Honduras
Hong Kong
Ireland
Israel
Italy (listing taken from http://sito.cineca.it/strutture/struttura)
Japan
Netherlands
New Zealand
Norway
Northern Ireland
The Philippines
Poland
Portugal
Scotland
Singapore
Slovenia
South Africa
Spain
Sweden
Switzerland
United States of America
Wales
International
... of "=", that will make it a perfect square trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), so we add the square of ...