Verified answer

Two brackets side by side means multiply.

What you do, is multiply each item in the first bracket with each item in the second.

So first of all, (-5) x (-1) is 5.

Then, (-c) x (-1) is just c.

They're both positive. Now put them side by side and you get:

5+c or c+5

5+c. I think its basically expanding the brackets