i do not get this

use division to determine whethe the binomial is a factor of f(x)

F(x)=x^3+20x-32; x-2

yes or no

3 is a factor of 12 because 3 divides exactly into 12 leaving no remainder

similarly if x-2 is a factor of x^3+20x-32 then it must divided exactly into it leaving no remainder.

so...
divide x^3+20x-32 by x-2 and see what happens.