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IMO Shortlist
2017 IMO Shortlist
N5
Weird expression being integer.
Weird expression being integer.
Source: IMO Shortlist 2017 N5
July 10, 2018
number theory
IMO Shortlist
Problem Statement
Find all pairs
(
p
,
q
)
(p,q)
(
p
,
q
)
of prime numbers which
p
>
q
p>q
p
>
q
and
(
p
+
q
)
p
+
q
(
p
−
q
)
p
−
q
−
1
(
p
+
q
)
p
−
q
(
p
−
q
)
p
+
q
−
1
\frac{(p+q)^{p+q}(p-q)^{p-q}-1}{(p+q)^{p-q}(p-q)^{p+q}-1}
(
p
+
q
)
p
−
q
(
p
−
q
)
p
+
q
−
1
(
p
+
q
)
p
+
q
(
p
−
q
)
p
−
q
−
1
is an integer.
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