(a+b)²-(a-b)²= 4ab

http://dmentrard.free.fr/GEOGEBRA/Maths/Export5/4abMD.html

http://dmentrard.free.fr/GEOGEBRA/Maths/Export5/4abMD.html

– Daniel Mentrard

Information: (a+b)²-(a-b)²= 4ab