This requires some thinking outside the box:

First pull out -1:

What we want to do now is apply the grouping technique:

However, we have to manipulate it in such a way so we can use it.

Note that -13*7=-91 and -24=39-63.

Now, let us rewrite the trinomial:

From the red group, factor out a 3q and from the blue group, factor out a -7.

Thus we now have:

Note that both terms have the same factor. Factoring out the blue term, we get:

Hope this makes sense!