Determine if −3, −23, −43, −63, ... is an arithmetic sequence. If it is, find the common difference.

It is an arithmetic sequence. Common difference: -20

Step-by-step explanation:

First we can find out if it is an arithmetic sequence by seeing how you get from -3 to -23. Then we see to get from -3 to -23, we need to subtract -20. It's the same with -43, so the common difference is -20. And since arithmetic sequences are the only ones common differences, then this is an arithmetic sequence. I hope this helps and I hope it's not wrong, but I do not think it is.