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Problems
Contests
National and Regional Contests
Turkey Contests
National Olympiad First Round
2007 National Olympiad First Round
3
3
Part of
2007 National Olympiad First Round
Problems
(1)
Turkey NMO 2007 1st Round - P03 (Algebra)
Source:
10/4/2012
Let
a
<
b
<
c
<
d
a<b<c<d
a
<
b
<
c
<
d
be integers. If one of the roots of the equation
(
x
−
a
)
(
x
−
b
)
(
x
−
c
)
(
x
−
d
)
−
9
(x-a)(x-b)(x-c)(x-d)-9
(
x
−
a
)
(
x
−
b
)
(
x
−
c
)
(
x
−
d
)
−
9
is
x
=
7
x=7
x
=
7
, what is
a
+
b
+
c
+
d
a+b+c+d
a
+
b
+
c
+
d
?
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
A
)
<
/
s
p
a
n
>
14
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
B
)
<
/
s
p
a
n
>
21
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
C
)
<
/
s
p
a
n
>
28
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
D
)
<
/
s
p
a
n
>
42
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
E
)
<
/
s
p
a
n
>
63
<span class='latex-bold'>(A)</span>\ 14 \qquad<span class='latex-bold'>(B)</span>\ 21 \qquad<span class='latex-bold'>(C)</span>\ 28 \qquad<span class='latex-bold'>(D)</span>\ 42 \qquad<span class='latex-bold'>(E)</span>\ 63
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
A
)
<
/
s
p
an
>
14
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
B
)
<
/
s
p
an
>
21
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
C
)
<
/
s
p
an
>
28
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
D
)
<
/
s
p
an
>
42
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
E
)
<
/
s
p
an
>
63