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Problems
Contests
National and Regional Contests
USA Contests
MAA AMC
AMC 12/AHSME
1986 AMC 12/AHSME
1
X and y.. plus and minus signs..
X and y.. plus and minus signs..
Source:
October 26, 2005
Problem Statement
[
x
−
(
y
−
x
)
]
−
[
(
x
−
y
)
−
x
]
=
[x-(y-x)] - [(x-y) - x] =
[
x
−
(
y
−
x
)]
−
[(
x
−
y
)
−
x
]
=
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
A
)
<
/
s
p
a
n
>
2
y
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
B
)
<
/
s
p
a
n
>
2
x
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
C
)
<
/
s
p
a
n
>
−
2
y
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
D
)
<
/
s
p
a
n
>
−
2
x
<
s
p
a
n
c
l
a
s
s
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
E
)
<
/
s
p
a
n
>
0
<span class='latex-bold'>(A)</span>\ 2y \qquad <span class='latex-bold'>(B)</span>\ 2x \qquad <span class='latex-bold'>(C)</span>\ -2y \qquad <span class='latex-bold'>(D)</span>\ -2x \qquad <span class='latex-bold'>(E)</span>\ 0
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
A
)
<
/
s
p
an
>
2
y
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
B
)
<
/
s
p
an
>
2
x
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
C
)
<
/
s
p
an
>
−
2
y
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
D
)
<
/
s
p
an
>
−
2
x
<
s
p
an
c
l
a
ss
=
′
l
a
t
e
x
−
b
o
l
d
′
>
(
E
)
<
/
s
p
an
>
0
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