I'm a student trying to go to Aussie to study where i got offers from both the cities. I dont know which city to choose?
Depends on your age and whether you like culture? Melbourne is full of both culture and oozing with social life to totally mess up your studying. You will find a cosmopolitan city filled with a deep history; galleries and museums. And of course, the beaches are still within reach. As are the other major cities.
Perth is a great place to study. It's smaller, simpler street layout so easier to navigate around. It doesn't have 10% of the culture of Melbourne and being in WA it is somewhat isolated from the rest of Australia. But, the weather is probably a little more predictable and fewer distractions if you need to really study hard!
If you aim to look around Australia during your free time, perhaps Melbourne would be the go.