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If 1/x + 1/y = 1/3, then
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22 Apr 2019, 09:08
22 Apr 2019, 09:08
Expert Reply
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Question Stats:
93% (00:29) correct
6% (00:51) wrong based on 15 sessions
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If \(\frac{1}{x} + \frac{1}{y} = \frac{1}{3}\), then \(\frac{xy}{x+y}\) =
A. \(\frac{1}{5}\)
B. \(\frac{1}{3}\)
C. 1
D. 3
E. 5
A. \(\frac{1}{5}\)
B. \(\frac{1}{3}\)
C. 1
D. 3
E. 5
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Joined: 10 Apr 2015
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Re: If 1/x + 1/y = 1/3, then
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23 Apr 2019, 05:59
23 Apr 2019, 05:59
1
Carcass wrote:
If \(\frac{1}{x} + \frac{1}{y} = \frac{1}{3}\), then \(\frac{xy}{x+y}\) =
A. \(\frac{1}{5}\)
B. \(\frac{1}{3}\)
C. 1
D. 3
E. 5
A. \(\frac{1}{5}\)
B. \(\frac{1}{3}\)
C. 1
D. 3
E. 5
Given: \(\frac{1}{x} + \frac{1}{y} = \frac{1}{3}\)
Find common denominator: \(\frac{y}{xy} + \frac{x}{xy} = \frac{1}{3}\)
Combine fractions: \(\frac{y+x}{xy} = \frac{1}{3}\)
Flip each fraction to get: \(\frac{xy}{x+y} = \frac{3}{1}\)
Answer: D
Cheers,
Brent
