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2019 Polish Junior Math Olympiad
2019 Polish Junior MO Finals
1.
1.
Part of
2019 Polish Junior MO Finals
Problems
(1)
Two integers
Source: Polish Junior Math Olympiad 2019 Finals
10/23/2020
Let
a
a
a
,
b
b
b
be the positive integers greater than
1
1
1
. Prove that if
a
b
,
a
−
1
b
−
1
\frac{a}{b},\; \frac{a-1}{b-1}
b
a
,
b
−
1
a
−
1
differ by 1, then both are integers.
number theory