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Re: 1/x + 1/y =6
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18 Mar 2018, 12:50
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).