Question

he decided to sell the car by passive voice

Answer 1

It was decided by him to sell the car.

I hope it helps you....

Answer 2

He decided that the car should be sold.

EXPLANATION:

In active voice, the sentence is of the form the subject performing an action on the object.

Example: she painted the wall.

In passive voice the sentence is of the form, the action is performed on the object by the subject.

Example: The wall was painted by her. In the given example if we move the object to the beginning it becomes ‘My car is to be sold has been decided by me’. The framing of the sentence is not good this way.

Hence the answer can be like a subject in the subject place and object in an object place and the action should be done.