Answer:

Step-by-step explanation:
This is horizontal parabola.
It has a directrix at x=-6.
The vertex is (0,0).
The focus is (6,0)
The equation of this parabola is of the form

Where (p,0) is the focus
By comparison, p=6
Therefore the equation of the parabola is

This implies that

Yes. all the friends will get at least one cup of juice
Substitution
y = 2x - 12
y = -x + 3
-x + 3 = 2x - 12
+ x + x
-----------------------------
3 = 3x - 12
+ 12 + 12
-----------------------
15 = 3x
------ ------
3 3
x = 5
y = 2(5) - 12
y = 10 - 12
y = -2
The final answer is (5,-2).