problem on inequality & exponent

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
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by Brent@GMATPrepNow » Sun Mar 11, 2012 7:19 am
alfat wrote:if (x-5)(y+2)=0 which of the following must be true?(A)X=Y (b) X>Y (C)X<Y (d)XY=-10 e.none of th above
If (x-5)(y+2)=0, then we can conclude that x = 5, or y = -2, or both

(A)X=Y This need not be true. For example, one solution could be x=5, y=6
(B) X>Y This need not be true. For example, one solution could be x=5, y=6
(C)X<Y This need not be true. For example, one solution could be x=5, y=3
(D)XY=-10 This need not be true. For example, one solution could be x=5, y=6
(E)none of the above.

So, the correct answer must be E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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