The question is a bit ambiguous: you may mean

or

Anyway, in both cases, the domain of a function involving a square root is found by imposing the content of the root to be greateer than or equal to zero. So, in the first case you have

In the second case, you have

The expression that represents the current price of milk is y +2.55. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.
B : Nonlinear system of inequalities
Answer:
i dont know which one to choose but chicken tenders