Can anyone help solving this ... (x-y)^4

[imane81]

What is the value of (x - y)^4?
(1)The product of x and y is 7.
(2)x and y are integers.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

[apuso]

(A)

since 7 is a prime number thus if x*y has to be 7 then its either x and y are 1 & 7 or -1 & -7...but in either of the cases the value of (x - y)^4 can be derived and would be the same.

whats the OA.

[aakar]

Has to be (C).

Statement I only tells you that XY = 7, but doesn't tell you that X and Y are integers as such X = 49 and Y = 1/7, X = 1/3 Y = 21 etc..

Statement II only tells you that X and Y are integers, not suff...

Both together tell you that X and Y are either 1, 7 or 7,1 or -1, -7 or -7, -1. In all cases x-y will give you 6 or -6, raised to the fourth give you the same answer...

[mehravikas]

Answer should be C

Statement 1 - x = 7, y = 1, or x = -7, y = -1, or x = 49, y = 1/7 satisfy the statement
Statement 2 - this tells us nothing but x and y are integers, they could be any integer

combining the statements - we get x = 7, y = 1 and x = -7, y = -1, but (x - y)^4 will have the same value irrespective of sign of x and y.

[thephoenix]

(A)

since 7 is a prime number thus if x*y has to be 7 then its either x and y are 1 & 7 or -1 & -7...but in either of the cases the value of (x - y)^4 can be derived and would be the same.

whats the OA.

but s1) never tells that x and y are int it can be 7/5*5 ; 7/2*2 ;7/3*3 and so on

it has to be C

[lalmanistl]

I agree C is the answer.