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National and Regional Contests
Greece Contests
Greece JBMO TST
2011 Greece JBMO TST
1
1
Part of
2011 Greece JBMO TST
Problems
(1)
2\sqrt {x-1} +4\sqrt {y-4} + 6\sqrt {z-9} = x+y+z
Source: Greece JBMO TST 2011 p1
4/29/2019
a) Let
n
n
n
be a positive integer. Prove that
n
x
−
n
2
≤
x
2
n\sqrt {x-n^2}\leq \frac {x}{2}
n
x
−
n
2
≤
2
x
, for
x
≥
n
2
x\geq n^2
x
≥
n
2
. b) Find real
x
,
y
,
z
x,y,z
x
,
y
,
z
such that:
2
x
−
1
+
4
y
−
4
+
6
z
−
9
=
x
+
y
+
z
2\sqrt {x-1} +4\sqrt {y-4} + 6\sqrt {z-9} = x+y+z
2
x
−
1
+
4
y
−
4
+
6
z
−
9
=
x
+
y
+
z
Inequality
equation
algebra