MathDB
Problems
Contests
National and Regional Contests
Russia Contests
All-Russian Olympiad Regional Round
2001 All-Russian Olympiad Regional Round
8.5
8.5
Part of
2001 All-Russian Olympiad Regional Round
Problems
(1)
|ax+b|+|cx+d|=|ex+f| - All-Russian MO 2001 Regional (R4) 8.5
Source:
9/25/2024
Let
a
,
b
,
c
,
d
,
e
a, b, c, d, e
a
,
b
,
c
,
d
,
e
and
f
f
f
be some numbers, and
a
⋅
c
⋅
e
≠
0
a \cdot c \cdot e \ne 0
a
⋅
c
⋅
e
=
0
.It is known that the values of the expressions
∣
a
x
+
b
∣
+
∣
c
x
+
d
∣
|ax+b|+|cx+d|
∣
a
x
+
b
∣
+
∣
c
x
+
d
∣
and
∣
e
x
+
f
∣
|ex+f|
∣
e
x
+
f
∣
equal at all values of
x
x
x
. Prove that
a
d
=
b
c
ad = bc
a
d
=
b
c
.
algebra