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August 12th, 2018, 05:13 PM   #1
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Reciprocal of x/y - 1

Which of the following equals the reciprocal of x/y - 1, where x/y - 1 does not equal zero?

(A) 1/x - y (B) -y/x (C) y/(x - 1) (D) x/(xy - 1) (E) y/(xy - 1)

My answer is x/y - 1 = (x - y)/y and its reciprocal is y/(x - y) but I am not able to get the right answer from the choices. Please help.
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August 12th, 2018, 06:15 PM   #2
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Originally Posted by bison72 View Post
Which of the following equals the reciprocal of x/y - 1, where x/y - 1 does not equal zero?

(A) 1/x - y (B) -y/x (C) y/(x - 1) (D) x/(xy - 1) (E) y/(xy - 1)

My answer is x/y - 1 = (x - y)/y and its reciprocal is y/(x - y) but I am not able to get the right answer from the choices. Please help.
You are correct. I can't think of a way to "massage" the other answers into the correct answer.

-Dan
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August 13th, 2018, 04:56 PM   #3
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You are correct. I can't think of a way to "massage" the other answers into the correct answer.

-Dan
If you view this as the fraction $\displaystyle x/y$ multiplied by $\displaystyle -1$ then B could be correct. On the other hand, who would interpret it this way?
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August 13th, 2018, 05:06 PM   #4
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If you view this as the fraction $\displaystyle x/y$ multiplied by $\displaystyle -1$ then B could be correct. On the other hand, who would interpret it this way?
I tried it as if it were intended to be x/(y - 1) since this is a very common mistake. But that doesn't help, none of the answers work.
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