Answer:
2
Step-by-step explanation:
GCF stands for the "greatest common factor." Therefore because 2 can go into both 2 and 4 evenly, it is the GCF.
X^4=256
x^4-256=0
(x^2)^2-(16)^2=0
(x^2+16)(x^2-16)=0
either x^2+16=0
it gives complex roots.
or x^2-16=0
or x^2-4^2=0
(x+4)(x-4)=0
either x+4=0,x=-4
or x-4=0
x=4
First, you must change all of this into improper fractions, like shown below.

Now you must change the sign.

Then we must reciprocalize 2/3.

Now we multiply, to get 2 4/10.
Guessing that the 3 was suppose to be an exponent.
The answer written in standard form is :
4x^3 + 10x - 4
This is called a cubic trinomial.