Bunuel wrote:
If xy > 0, 1/x + 1/y = 5, and 1/xy = 6, then (x+y)/5 = ?
A. 1/25
B. 1/6
C. 1/5
D. 5
E. 6
HarrishGowtham wrote:
Answer is B.
(1/X+1/Y)=5 canbe solved as {(x+y)/xy}=6. Substituting for 1/xy=6, we get
x+y=5/6
==> (x+y)/5= 5/(6*5)=1/6.
I am stuck trying to understand this explanation. I got the right answer, but not this way.
\(\frac{1}{x}+ \frac{1}{y} = 5\)
\((\frac{1}{x}+ \frac{1}{y}) = \frac{x + y}{xy}\)
Aren't the two RHS equivalent?
Quote:
(1/X+1/Y)=5 can be solved as {(x+y)/xy}=6.
Can anyone explain the steps from the first part of the above sentence to the last part? If the two RHS above quote are equivalent, where does "= 6" come from?
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