2x - 1
If p(1/2) gets a remainder of 0, that means that when that when x=1/2, that 1/2 multiplied by some number minus a different number equals 0. To solve this, plug x = 1/2 into the above expressions:
(1/2) - 2 = -3/2 ≠ 0
(1/2) + 1 = 3/2 ≠ 0
2(1/2) -1 = 0
So 2x - 1 is the answer
