How can the techniques of factoring be extended to work with higher-degree polynomials?

Any techniques that you're familiar with can be applied to polynomials of any degree. These might include ...

Each root you find can be factored out to reduce the degree of the remaining polynomial factor(s).

answer:   35 % is the probability of a late departure or an early arrival.

step-by-step explanation:

let l represents the late departure and e represents the early departure.

then, according to the question,

p(l) = 12 %,   p(e) = 27 % and = 4 %

and, we have to find out,

but, we know that,

which is the required equation that will use to find the probability of a late departure or an early departure.

therefore,   the probability of a late departure or an early arrival =   35 %