Developed countries have better medical facilities because they have more money and are able to afford equipment which is often very expensive. Due to having more money, their medical facilities can be equipped more expensively. While this doesn't always mean it is a better facility, it often is the case.
So in a nutshell, because developed countries have more money, they are also able to provide better healthcare and better medical care in their medical facilities.
All of them Plays an equal and important role to support life on Earth..
By rename do you mean turn into an improper fraction?
if so, it is because without turning it into an improper fraction, you cannot subtract 3/4 from 1/4 because you would get a negative answer and that would be incorrect
People migrate to the new lands, populate, build cities, created businesses, trade, settle.
