Describe a situation that can be modeled by the expression \large x-8.

Given that (x-3) is a factor of f(x)=x^3+ax^2-x-6, find a and hence the number of real roots or the equation f(x)=0

I'm terrible at math any here is appreciated.

What is the equation of the following graph in vertex form? parabolic function going down from the left through the point zero comma twelve and through the point two comma zero and turning at the point four comma negative four and going up through the point six comma zero and continuing towards infinity courtesy of texas instruments a: y = (x − 4)2 − 4 b: y = (x + 4)2 − 4 c: y = (x + 2)2 + 6 d: y = (x + 2)2 + 12