Looks like this question reads in English:

How to find a domain 

f (x) = x^2 -x + 3

And how can I find ranges

y = f (x) -g (x)

if its function is known

f (x) = x 2 -x + 3 and g (x) = 3x-5?

This is great. Thank you @acer , @Kitonum , @Carl Love and @mmcdara  for your enhancements.