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PEN F Problems
9
F 9
F 9
Source:
May 25, 2007
geometry
3D geometry
rational numbers
Problem Statement
Prove that every positive rational number can be represented in the form
a
3
+
b
3
c
3
+
d
3
\frac{a^{3}+b^{3}}{c^{3}+d^{3}}
c
3
+
d
3
a
3
+
b
3
for some positive integers
a
,
b
,
c
a, b, c
a
,
b
,
c
, and
d
d
d
.
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