Matrix Equation Absolute Difference

Let A=[

1	−1
2	α

] and B=[

β	1
1	0

],α,β∈R. Let α1 be the value of α which satisfies (A+B)2−A2+[

2	2
2	2

] and α2 be the value of α which satisfies (A+B)2−B2. Then |α1−α2| is equal to _______.