Greetings!Simplify the Expression.
Distribute the Parenthesis.
How? Multiply the terms inside the Parenthesis by the term outside of the Parenthesis.
Combine Like Terms.

![\left[\begin{array}{ccc}8x^2-12x\end{array}\right]](https://tex.z-dn.net/?f=%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D8x%5E2-12x%5Cend%7Barray%7D%5Cright%5D%20)
Hope this helps.
-Benjamin
(4 + 2x)(6 + 2x) =
4(6 + 2x) + 2x(6 + 2x) =
24 + 8x + 12x + 4x^2 =
4x^2 + 20x + 24 <==
(-2,-4) is the correct answer.
Hope this helps:)
First you have all ten books, but then every time after, you loose one because you can't put the same book in the group twice.
10 * 9 * 8 * 7 = 5040 groups