I just hit Virtuoso part in 1 day

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

Vip at (-2,7) dropped her pass and moved to the right on a slope of -9 where can you catch up to her to return her vip pass

How can you find the conditional probability of a given b as the fraction of b’s outcomes that also belong to a, and interpret the answer in terms of the model? i just need a good explanation