Question

Factor the four-term polynomial.
ab + ac - 4b - 4c

Answer 1

Group therm first, like this:
(ab + ac) - (4b + 4c)
It doesn't look like we did much, but you can see more clearly how to proceed with factoring from here :)
can you do the rest?

Answer 2

So, factor out a from (ab + ac)
and factor out 4 from (4b + 4c)
you'll end up with
a(b + c) - 4(b + c)

Now you can treat (b + c) as a monomial that you can factor out :
(b + c)(a - 4)

And that's your factored form!
:D