X^2 -2XY +Y^2=36 so X-Y =?
My solution:(Not so sure...)
X^2 -2XY +Y^2=(X - Y)^2
Therefore, (X - Y)^2=36 So, X-y=6
But it is also a choice question and here are the choices:
6
+-6 (Postive or negative six) (could it be?)
-6
18.
Thank you in advance!
The +- solution is correct.
How ?,how could i know
If x - y = 6 then (x - y)^2 = ( 6 )^2 = 36
If x - y = - 6 then (x - y)^2 = (-6)^2 = 36
