x²+ax = ... = (x+a/2)²-(a/2)² (visual proof)

http://dmentrard.free.fr/GEOGEBRA/Maths/Export5/x%C2%B2+axMD.html
http://dmentrard.free.fr/GEOGEBRA/Maths/Export5/x%C2%B2+axMD.html
– Daniel Mentrard

Information: x²+ax = ... = (x+a/2)²-(a/2)² (visual proof)