The difference between 'berjaja' and 'menjajakan'

Some users of the Malay language often use 'menjaja' in sentences such as
'Lelaki itu menjaja kuih muih di luar pasar itu.'.

There is no such word in the Malay language but 'menjajakan' exists. Hence the sentence should have been written as

'Lelaki itu menjajakan kuih-muih di luar pasar itu.' (The man is selling various types of 'kuih' (Malay cakes) by calling out their names outside the market.)

The is another word which means 'hawking' too. It is 'berjaja' and you can use it without an object as it is an intransitive as opposed to 'menjajakan' which is transitive in nature.

A sentence containing 'berjaja' can be as follows:
Hashim berjaja untuk menyara keluarganya. [Hashim sells things by shouting out their names as a means to support his family.]

Hence, the difference between 'berjaja' and 'menjajakan' is the former is a intransitive verb whereas the latter is a transitive one.