Quadratic Equations

Let a, b be the solutions of x² + px + 1 = 0 and c, d be the solution of x² + qx + 1 = 0. If (a \(-\) c) (b \(-\) c) and (a + d)(b + d) are the solution of x² + ax + \(\beta\) = 0, then \(\beta\) is equal to