Expand and simplify: (a+b)2(a−b)2(a + b)^2 (a - b)^2(a+b)2(a−b)2.
a4−2a2b2+b4a^4 - 2a^2b^2 + b^4a4−2a2b2+b4
a4−b4a^4 - b^4a4−b4
a4+2a2b2+b4a^4 + 2a^2b^2 + b^4a4+2a2b2+b4
(a−b)4(a-b)^4(a−b)4