Question 6925
You check if one function is a factor of another by dividing it into the function. If you get a 0 remainder, it divides it evenly and is a factor. The value of x that makes the binomial 0 is a solution of the function.
{{{3^3+5x^2+x+6}}} divided by {{{x-4}}} gives {{{3x^2-7x-27}}} and a remainder of {{{-102/(x-4)}}}.
However, x+2 divides the function evenly (try it!), so -2 is a root of the function.