Hadi B. answered 04/01/19
BS in Mathematics with 5+ years of tutoring experience
since the zeros are -3,-1,2,4 we know we have the factors,
(x+3) (x+1) (x-2) (x-4)
multiplying these factors together will give a 4th degree polynomial with leading coefficient 1 and integer coefficients
(x+3)(x+1)(x-2)(x-4)
= (x2+4x+3)(x2-6x+8)
= x2(x2-6x+8)+4x(x2-6x+8)+3(x2-6x+8)
= x4-2x3-13x2+14x+24