Hi! 1 is a root of your polynomial, so by polynomial long division you can find out the factors.
Ok I redid it and think I got the right answer, I first took
2x^3 + x^2 - 2x - 1
(2x^3 + x^2) - (2x - 1)
x^2( 2x + 1) + 1(2x + 1) found the common factor(not sure if thats the right term)
So my final answer would be
(2x + 1)(x^2 +1) Again this is factoring by grouping so if anyone has any input thanks