So...
x=3

and you have 2x³-4x²-5x-3=0
when x=3 is a factor.

=?Using divison from x-3 gives us 2x²+2x+1

=>Using b² -4ac, this quard. has no real roots...therefore, the answer will contain a complex number.

=>Using the quard. forumla...where a=2 b=2 c=1
giving us -2+ or - √-4/4

The answer comes to 1/2+ or - 1/2 i

which as you can see...are complex conjugate pairs.
The factors are
x= 1/2 +1/2i
x= 1/2 - 1/2i
x=3

Take a walk with me?