Question

Has he helped them? (into passive)with explanation plz today is my grammar exam​

Answer 1

Have they been helped by him?
The subject in the sentence is “he”, and the object is “them”.
So, to turn the active-voice (the stress is put on the subject) sentence “Has he helped them?” into a passive-voice (the stress is put on the object) sentence, you have to change it to “Have they been helped by him?” by putting the object with the verb and putting the subject after with “by”.

Answer 2

Answer:

Have they been helped by he?