Answers

2014-02-24T19:28:09+05:30
Clearly, we need to eliminate b,c from the left hand side
Assuimng a⋅b⋅c⋅d≠0,
 
As ba=cb=dc, we have b2=ca,c2=bd,ad=bc

(b−c)2+(c−a)2+(d−b)
2
=b2+c2−2bc+c2+a2−2ca+d2−2bd+b2
=a2+d2+2(b2+c2−bc−ca−bd)

=a2+d2+2(ca+bd−ad−ca−bd)

=a2+d2−2ad=(a−d)2

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