What is the common difference in the following arithmetic sequence?

7, 3, –1, –5,

Step-by-step explanation:

The common difference of an arithmetic sequence is the difference in next term minus term before it.

We can check by taking all of the terms in the sequence given. the common difference will be same for all.

As you can see, the common difference is  

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!