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2017 Moscow Mathematical Olympiad
7
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Source: Moscow Math Olympiad 2017, Grade 11, P7
April 25, 2017
algebra
geometric sequence
Problem Statement
(
a
i
)
,
(
b
i
)
(a_i),(b_i)
(
a
i
)
,
(
b
i
)
are nonconstant arithmetic and geometric progressions.
a
1
=
b
1
,
a
2
/
b
2
=
2
,
a
4
/
b
4
=
8
a_1=b_1,a_2/b_2=2,a_4/b_4=8
a
1
=
b
1
,
a
2
/
b
2
=
2
,
a
4
/
b
4
=
8
Find
a
3
/
b
3
a_3/b_3
a
3
/
b
3
.
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