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Re: 1/x + 1/y =6 [#permalink]
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FatemehAsgarinejad wrote:
The question is wrong!


Yeah.. Fixed my bad
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Re: 1/x + 1/y =6 [#permalink]
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Explanation

Using the Bowtie method, you find that \(\frac{x+y}{xy}\)=6.

By multiplying both sides of the second equation by \(\frac{-1}{2}\), you find that \(\frac{1}{6}=\frac{zy}{z+y}\).

Flipping both fractions yields \(\frac{z+y}{zy}=6\), and thus, \(\frac{z+y}{zy}=\frac{x+y}{xy}\).

Inspecting the two fractions, you may realize that z must equal x.

Alternatively, by applying the Bowtie again, you obtain \(\frac{y + x}{zy} = \frac{z + y}{xy}\), and thus \(zy^2 +
xyz = xyz + xy^2\), meaning \(zy^2 = xy^2\), or z = x, so the answer is choice (C).
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Re: 1/x + 1/y =6 [#permalink]
answer: C
1/x + 1/y = 6
(x + y) / xy = 6

-1/3 = -2 (zy/(z + y))
(z + y) / zy = 6

(x + y) / xy = (z + y) / zy
(x + y) / x = (z + y) / z
1 + y/x = 1 + y/z
y/x = y/z
1/x = 1/z
x = z
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Re: 1/x + 1/y =6 [#permalink]
Answer is C

Expand the 1st given Equation and you get 6 = x+y / xy

Expand the 2nd Eqn and you will get 1/6 = zy/y+z

Substitute the value of 6 from 1st Equation and you get the answer after cancelling the common terms both sides.
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Re: 1/x + 1/y =6 [#permalink]
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