i need help on these.
1) find remaining zeros for
7x^5+4x^4+14x^3+8x^2-441x-252
AND
2) 3x^4+13x^+17x^2+117x-90
WHEN the only zero given for Both is -3i
someone please help i have bee on these for too long.

Question

i need help on these. 
1) find remaining zeros for 
7x^5+4x^4+14x^3+8x^2-441x-252
AND
2) 3x^4+13x^+17x^2+117x-90 
WHEN the only zero given for Both is -3i
someone please help i have bee on these for too long.

helder_edwin · Answer

if you know something about complex numbers then, if -3i is a zero (root) of the given polynomials, then 3i is also a root.
this means that both polynomials can be exactly divided by
$$ \Large (x+3i)(x-3i)=x^2-(3i)^2=x^2+9 $$

anonymous · Answer

divede them both by x^2+9, and get the remainging zeros from the quotient?

helder_edwin · Answer

it HAS to be zero, otherwise something is wrong with the polynomials you wrote down

anonymous · Answer

right, but the first one should be 5 zeros, and i only have -3i, and 3i

helder_edwin · Answer

yes i know but the quotient you get from the division MIGHT be easier to factor i guess

anonymous · Answer

3 and 3?

anonymous · Answer

i have this paper full of numbers and nothing is working, i might just give it a little break i dno

helder_edwin · Answer

i worked with the second polynomial i got this:
$$ \Large 3x^4+13x^3+17x^2+117x-90=(x^2+9)(3x^2+13x-10) $$
right?