The answer is B, 5/6, because when you multiply 4 by 5 it is 20, and when you multiply 5 by 6, you get 30, so 20/30. And, 20/30=2/3. I hope I answered your question!
Answer:
Part 1)
----->
Part 2)
----> 
Part 3)
----> All real numbers
Part 4)
----> 
Step-by-step explanation:
we know that
The domain of a function is the set of all possible values of x
Part 1) we have

we know that
In a quotient the denominator cannot be equal to zero
so
For the value of x=0 the function is not defined
therefore
The domain is

Part 2) we have

we know that
In a quotient the denominator cannot be equal to zero
so
For the value of x=-4 the function is not defined
therefore
The domain is

Part 3) we have

Applying the distributive property

This is a vertical parabola open upward
The function is defined by all the values of x
therefore
The domain is all real numbers
Part 4) we have

we know that
In a quotient the denominator cannot be equal to zero
so
Equate the denominator to zero

Remember that

(
The solution is x=-4
so
For the value of x=-4 the function is not defined
therefore
The domain is

11.25cups. I got that by multiplying 2.5. by 4.5. If she wants to make 4.5 batches and 1 batch uses 2.5 cups, you have to multiply the cups of 1 batch by the number of batches she wants to make.