Explanation:
We have
Which is the same as
To expand this polynomial, we can use the FOIL method. Meaning that we multiply the Fronts, Outsides, Insides, and Lasts together and then add each of these products.
The two fronts are
and
,
The two Outsides are
and
,
The two Insides are
and
,
The two lasts are
and
,
Now we just need to add these together to get