Istill don’t understand how to get the answer

Step-by-step explanation:

First, lets think of this binomial as

To do this, we will have to use the FOIL method. This means that we multiply the First terms, Outside terms, Inside terms, and Last terms.

The first terms are both , so lets multiply these first

Next lets multiply the outside terms, which are and

Now the inside terms, which are also and

Lastly, the last terms, which are both

Now we have to add each of these together.

The last step is to combine like terms

This gives us

10 - 8 = -2

  8 - 6 = -2

etc, so -2 is the common difference

step-by-step explanation: