We're given [tex]f(x) = 0[/tex] when [tex]x=-2[/tex] and [tex]x=3[/tex], so both [tex]x+2[/tex] and [tex]x-3[/tex] divide [tex]f(x)[/tex]
We're also told [tex]2x^2+3x+2[/tex] divides [tex]f(x)[/tex]. This quadratic does not have roots at -2 or 3, so we can factorize [tex]f(x)[/tex] as
[tex]f(x) = 2 (x + 2) (x - 3) (2x^2 + 3x + 2)[/tex]
where the leading coefficient is 2 because the full expansion should have a leading term of [tex]4x^4[/tex].
Now just expand [tex]f(x)[/tex] :
[tex]f(x) = 2 (x + 2) (x - 3) (2x^2 + 3x + 2)[/tex]
[tex]f(x) = 2 (x^2 - x - 6) (2x^2 + 3x + 2)[/tex]
[tex]f(x) = 2 (2x^4 + x^3 - 13x^2 - 20x - 12)[/tex]
[tex]f(x) = \boxed{4x^4 + 2x^3 - 26x^2 - 40x - 24}[/tex]
