Ну давай, ага, давай, ну ладно, давай!(Ok let it be, ok, ok, ok bye”)

There is the word “Давай” in Russian language. Actually, this is the verb ДАВАТЬ in imperative mood. So, the plural imperative form is ДАВАЙТЕ. Давай and Давайте. Let’s consider the meanings of this word:

Давай! – it can mean “bye!”, just a quick “bye”, usually in end of phone conversation.

Давай also has its literal meaning – give!

Давай! can mean “go ahead!”

The phrase “да, давай” can also mean “let’s do it” or “let it be”

In context it can mean “let us(let’s)”, for example: ДАВАЙ СДЕЛАЕМ – let’s make/do.

And also Давай in some context can mean “okay let’s go”, for example “Давай  поедем на дачу? Давай!” – let’s go to the country house? okay let’s go!