One root of 2x^3 - 5x - 3 = 0 is x = -1. Call that a lucky guess.
Therefore x+1 is one factor. Divide that into 2x^3 - 5x - 3 and you get the other factor to be (2x^2 -2x -3). That can be factored again using the quadratic equation. The remaining roots are
[4 +/- sqrt(28)]/4 = 1 +/- (1/2)sqrt7
So I end up with factors of
(x+1)(x -1 + (1/2)sqrt7)(x -1 -(1/2)sqrt7)
Don't trust my algebra. Check it yourself.
how do u factor out 2x^3 - 5x - 3
1 answer