Can I use equity for a down payment?

[Aryelle Collins]

I'm looking at a duplex in St. Petersburg being sold for 85k (accepting all offers) ARV 120k needing about 7500 in repairs. The seller says there is a high amount of equity for this property. Can I use some of the equity as a down payment and can you explain how that works? Also what kind of terms would make this deal work if I were to use the equity?