Answer:
The books were left by someone on table.
Step-by-step explanation:
Passive voice can be defined as a verb in passive voice in which the subject receives action by the object of a sentence.
For example, The house was cleaned by me.
In this sentence, the subject 'the house' is receiving action by object 'me.'
The given sentence, after changing to passive voice would be:
'The books were left by someone on table.'
The action of verb is changed from 'somebody' performing an action to an action performed by 'someone.'