What is the remainder when (x3 - 6x2 - 42x + 79) is divided by (x + 5) ?

We can do synthetic division to solve this or just normal division. Either way, the remainder would be:

-406 / (x+5)

The whole result is this:

(x3 - 6x2 - 42x + 79) / (x+5) = x2 - 11x + 97 - 406 / (x+5)

With the remainder as - 406 / (x+5)