63 dollars 3 hours
21 dollars 1 hour
Shifting a graph up by c units involves adding c to the whole function
therefor
y=ax^2+c is c units higher than y=ax^2 (aka, it is shifted c units up)
The first thing we must do for this case is to define variables:
We have then:
x: liz's age
y: melinda's age
We now write the system of equations:

By solving the system graphically we have that the age of each one is currently:

Next year, the age of liz is:
Answer:
Next year, Liz's age is 11 years.
Note: see attached image for the graphic solution.
More than one liter because it only depends how bog your sink is...I believe it is more than one liter