What if you mix red paint and blue paint?

Topic:
Equations
Move the button to see different quantities of red and blue paint. If you mixed those quantities of red and blue paint, what color would it make? Would it always make the exact same shade? If x = 6, what is y? If x = 7, what is y? If x = 5.5, what is y? If y = 15, what is x? If y = 21, what is x? If y = 20, what is x? How are x and y related? Can you write an equation to relate x and y?