MathDB
Problems
Contests
International Contests
Junior Balkan MO
2010 Junior Balkan MO
1
JBMO 2010. Problem 1.
JBMO 2010. Problem 1.
Source:
June 20, 2010
algebra
polynomial
function
algebra proposed
Problem Statement
The real numbers
a
a
a
,
b
b
b
,
c
c
c
,
d
d
d
satisfy simultaneously the equations
a
b
c
−
d
=
1
,
b
c
d
−
a
=
2
,
c
d
a
−
b
=
3
,
d
a
b
−
c
=
−
6.
abc -d = 1, \ \ \ bcd - a = 2, \ \ \ cda- b = 3, \ \ \ dab - c = -6.
ab
c
−
d
=
1
,
b
c
d
−
a
=
2
,
c
d
a
−
b
=
3
,
d
ab
−
c
=
−
6.
Prove that
a
+
b
+
c
+
d
≠
0
a + b + c + d \not = 0
a
+
b
+
c
+
d
=
0
.
Back to Problems
View on AoPS