(x - p)(2x + 1) = 02x2 + x - 2px - p = 02x2 + x (1 - 2p) - p = 02x2 - (2p - 1)x - p = 0divide through by 2x2 - (2p−1)2x - p2 = 0compare to x2 - (sum of roots)x + product of roots = 0sum of roots = 2p−12But sum of roots = 1Given; 2p−12 = 12p - 1 = 2 x 12p - 1 = 22p = 2 + 1 = 3p = 32p = 112
