I am not sure how to post an entry when there is capital gain such as sold equipment for 700 paid 2000 for it with a accumulated depreciation of 1500.
Debit cash700
Credit equipment 700
How do I post the capital gain of 200?

The Equipment is on your books as a debit of 2,000. You sold that, so you must get rid of that by crediting it for 2,000

Accumulated Depreciation is on your books as a credit of 1,500. You must get rid of that too by debiting it.

You sold it for cash for 700 (debit).

The difference b/w debits and credits will indicate if it is a loss or gain (loss – debit; gain – credit)

Dr. Accumulated Depreciation 1,500
Dr. Cash 700
Cr. Equipment 2,000
Cr. Gain 200 (this is just a plug. Debits total 2,200 and credits 2,000, so therefore the plug is 200 credit, which means a gain)

Thank you