Hello lilly

The major product forms from SN1 ; the alkyl bromide is tertiary, so it is bulky/sterically-hindered , and is more likely to lose Br− as a leaving group before managing to get attacked by a nucleophile (ethanol). The proton on the attached ethanol then dissociates on its own.

That is characteristic of a first -order process, where the slow step is the departure of the leaving group and a carbocation intermediate forms (here, a tertiary carbocation).

There is a minor product from E1 , but this is very minor unless the temperature is sufficiently high. This would be a β elimination, i.e. the alcohol extracts a proton from the carbon adjacent to Br and patches up the carbocation intermediate.

Thank you