x2 - y2 IS factorable exactly as you have done.
On the other hand, expressions such as x2 + 4 or x2 + 3x + 7 are not factorable over the reals.
David W.
Use F-O-I-L on (x+y)2
x2 + 2xy + y2
That is not x2 + y2 (unless either x=0 or y=0, or both, since 2xy must be 0)
Report
09/03/16
Eve S.
Can't you factor x^2+y^2 to be the same?
Report
09/03/16
Mark M.
tutor
Try it with numbers. For example, let x = 3 and y = 4. Then, x2 + y2 = 9 + 16 = 25, but (x+y)2 = 72 = 49
So, x2+y2 ≠ (x+y)2.
Report
09/03/16
Eve S.
09/03/16