Question

He is inviting all his friends (begin each)

Answer 1

The question is asking us to start the provided statement with "Each."

So, here is your sentence:

Each of his friends is being invited by him.

Explanation:

See, this is really simple. It's like the 'active to passive conversion'(apc). When the query stated to create the statement with 'each', the places of the nouns interchange- as mandatory in the 'apc'. So, the tense also changes.