- Joined
- May 25, 2008
- Messages
- 45
- Reaction score
- 0
If x^2 - 2 x y + Y^2 = 2 and xy=2, which of the following is true?
1) x=y
2) x= y+1
3) x= y-1
4)x=y+2
5)x= y-2
So the answer in crack exp is 1)x=y . Is this wrong or I don't see it? howcome xy=2 and x=y??
The explanation says (x-y)^2= 2-xy ---> (x-y)^2= 0 --> x=y
1) x=y
2) x= y+1
3) x= y-1
4)x=y+2
5)x= y-2
So the answer in crack exp is 1)x=y . Is this wrong or I don't see it? howcome xy=2 and x=y??
The explanation says (x-y)^2= 2-xy ---> (x-y)^2= 0 --> x=y