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Tìm kiếm x y z
x-1/y =1
y-1/z =1
z-1/x =1

User Molamk
by
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1 Answer

4 votes

y - 1/z = 1 ==> y = 1 + 1/z

z - 1/x = 1 ==> z = 1 + 1/x

==> y = 1 + 1/(1 + 1/x) = 1 + x/(x + 1) = (2x + 1)/(x + 1)

x - 1/y = x - (x + 1)/(2x + 1) = (2x ² - 1)/(2x + 1) = 1

==> 2x ² - 1 = 2x + 1

==> 2x ² - 2x - 2 = 0

==> x ² - x - 1 = 0

==> x = (1 ± √5)/2

If you start solving for z, then for x, then for y, you would get the same equation as above (with y in place of x), and the same thing happens if you solve for x, then y, then z. So it turns out that x = y = z.

User Funkatron
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