Tricky one!!

[gmatblood]

If x and y are integers such that x < y < 0, what is x - y?

(1) (x + y)(x - y) = 5

(2) xy = 6

[shankar.ashwin]

A IMO.

(1) x^2 - y^2 = 5 ( 9 - 4 is the only combination which gives 4)
x=-3 and y=-2. Suff

(2) xy=6
(-1*-6 / -2*-3) 2 possibilities. Insuff

[bpdulog]

It is A. When you translate 1, you get x^2-y^2 = 5. The only possible choice is -3 and -2.

For B, you can have -6 and -1 in addition to -3 and -2.

[GMATGuruNY]

If x and y are integers such that x < y < 0, what is x - y?

(1) (x + y)(x - y) = 5

(2) xy = 6

Statement 1: (x + y)(x - y) = 5.
To yield a product of 5, only two combinations of factors are possible: 5 and 1, -5 and -1.
Since x and y are both negative integers, the factors needed here are -5 and -1.
Since it's not possible that x+y = -1 (the sum of two negative integers cannot be -1), we know that x+y = -5 and that x-y = -1.
SUFFICIENT.

Statement 2: xy=6.
If x=-6 and y=-1, then x-y = -6-(-1) = -5.
If x=-3 and y=-2, then x-y = -3-(-2) = -1.
INSUFFICIENT.

The correct answer is A.