Respuesta :

where there is a zero, a+bi, there is a zero, a-bi

therfor since there is a zero 0+5i, there is also a zero 0-5i

zeroes are 4, 5i,-5i
for zeroes
r1,r2,r3
the factors are
(x-r1)(x-r2)(x-r3)

so
(x-4)(x-5i)(x+5i)
expand
f(x)=x^3-4x^2+25x-100