GMAT Prep?? (X quadrant)

dferm wrote:Please Help...

Thanks..

The only way that (-a, b) and (-b, a) are in the same quadrant is if they're both negative or both positive. If both a and b are positive, when apply the - and get (-, +) and (-, +) so the coordinates are in quad II. When both are negative, we get (+,-) (+,-) and quad IV.

So, we need to determine which quad (a,b) is in and then figure out which one (-x,y) is in.

Statement 1: xy > 0
x & y have the same sign- thus (-x,y) will be in either quad II or IV. Insufficient

Statement 2: ax > 0.
a & x have the same sign. By itself, we still don't know anything about y. Isufficient.

Together:
Sufficient- we know that x,y and a,b have the same sign. We don't know which quad they'll all be in, but we know that they'll be in the same one.