We'll take logarithms both
sides:
log [x^(b+c)*y^(c+a)*z^(b+a)] = log 1
(*)
We'll transform the logarithm of the product into a
sum:
log [x^(b+c)*y^(c+a)*z^(b+a)] = log x^(b+c) +
logy^(c+a) + log z^(b+a)
We'll use the power property of
logarithms:
log x^(b+c) = (b+c)*log
x
logy^(c+a) = (c+a)*log y
log
z^(b+a) = (b+a)*log z
The relation (*) will become
(1):
(b+c)*log x + (c+a)*log y + (b+a)*log z =
0 (1)
But, from enunciation, we'll
have:
(Log x)/(b-c) = (Log y)/(c-a) = (Log
z)/(a-b)
We'll cross
multiply:
(Log x)*(c-a) = (Log
y)*(b-c)
Log y = (Log
x)*(c-a)/(b-c)
Log z = (Log
x)*(a-b)/(b-c)
So, the relation (1) will become
(2):
(b+c)*Log x + (c+a)*(Log x)*(c-a)/(b-c) + (b+a)*(Log
x)*(a-b)/(b-c) = 0
We'll factorize by log
x:
log x [b+c + (c^2-a^2)/(b-c) + (a^2 - b^2)/(b-c)] =
0
We'll divide by log x and we'll remove the
brackets:
b^2 - c^2 + c^2-a^2 + a^2 - b^2 =
0
We'll remove like terms and we'll
get:
0 =
0
So,
x^(b+c)*y^(c+a)*z^(b+a)=1 if and only if (Log x)/(b-c) = (Log y)/(c-a) = (Log
z)/(a-b).
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