x-y=12and 1/x-1/y=3. How much is x*y Possibly answers -6,6,-4,4
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calendarEducator since 2010
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We have the equations x - y = 12 and ( 1/x) - ( 1/y) = 3. We have to determine x*y.
( 1/x) - ( 1/y) = 3
=> y/xy - x/xy = 3
=> (y - x) = 3xy
but we know x - y = 12
=> y - x = -12
(y - x) = 3xy
=> -12 = 3xy
=> xy = -12/ 3
=> xy = -4
The required value of xy = -4
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calendarEducator since 2011
write51 answers
starTop subjects are Math and Literature
Given that x-y = 12 and 1/x -1/y = 3, we are to find x*y.
=> 1/x -1/y = 3
=> [xy/1] [1/x -1/y] = 12
=> (y - x) /xy = 3
=> 3xy = y - x
=> -3xy = x - y
=> -3xy = 12
=> (-3xy)/-3 = 12/-3
=> xy = -4
The correct answer is x * y = -4
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