The quadratic equation [tex]y = ax^2 +bx+c[/tex] can be written in the form:
[tex]y = a(x-p)(x-q)[/tex]
Where p and q are the roots of the equation.
Given p = 4, q = -2, a = 3, the quadratic will look like this:
[tex]y = 3(x-4)(x+2)[/tex]
Finally, distribute and combine like terms to put it in standard form.
[tex]y = 3(x^2 - 4x+2x -8) \\ \\ y = 3(x^2 -2x-8) \\ \\ y = 3x^2 -6x -24[/tex]