Question

Change into passive voice- Tom painted the entire house

Answer 1

active voice- Tom painted the entire house
passive voice- The entire house was painted by Tom.

Answer 2

The answer is: The entire house is painted by Tom.  

The sentence is written in passive voice and here the subject in the active voice sentence (Tom) has been changed into object and the object (the entire house) has been changed into the subject.

The verb has remained the same, painted. The subject verb agreement has been well maintained by the sentence.