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MathLinks Contest 7th
1.2
0712
0712
Source:
April 14, 2008
algebra
polynomial
number theory
greatest common divisor
quadratics
calculus
integration
Problem Statement
Let
a
,
b
,
c
,
d
a,b,c,d
a
,
b
,
c
,
d
be four distinct positive integers in arithmetic progression. Prove that
a
b
c
d
abcd
ab
c
d
is not a perfect square.
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