Answer :

f(x) = (0x - 3)(x + 4)
         0x - 3 = 0  or  x + 4 = 0
             + 3 + 3           - 4  - 4
                0x = 3             x = -4
                 0     0
                  x = 0
f(x) = (0x - 3)(x + 4)
f(3) = (0(3) - 3)(3 + 4)
f(3) = (0 - 3)(7)
f(3) = (-3)(7)
f(3)= -21
(x, f(x)) = (3, -21)
or
f(x) = (0x - 3)(x + 4)
f(-4) = (0(-4) - 3)(-4 + 4)
f(-4) = (0 - 3)(0)
f(-4) = (0)(0)
f(-4) - 0
(x, f(x)) = (-4, 0)
Assuming there really is 0

[tex]f(x)=(0x-3)(x+4)=-3(x+4)=-3x-12\\\\ -3x-12=0\\ -3x=12\\ \boxed{x=-4}[/tex]