There is no point in casting Ebony Flesh after Dragonhide since the game only gives you 80% damage reduction, so casting Ebony Flesh would only be redundant anyway. To Clarify, you will not gain benefit from both even if it were possible for them to be used at the same time
Thank you for the fast reply

So dragonhide is better?...or is Ebonyfleash better???...take note i have all of alteration maxed, 3 points on that perk that makes fleash armors stronger...does that perk also effect dragonhide???