The end of the ray stops the x values from proceeding left at x=0. So your domain is from that point on to infinity. In your solution set x >= 0, since the arrow continues on the right side where x's are positive.
Let's call Tacos t and Enchiladas e.
Lily paid $9 for 2t and 3e
Alex paid $12.50 for 3t and 4e.
Thus the equations would be.

Answer:
1.) How many square feet of flooring can Tad install in eight hours? 384 square feet
2.) How many square feet of flooring can Janice install in five hours? 480 square feet
3.) If they each work for 12 hours, how many square feet of flooring can they install? 1,728 square feet.
I hope i helped alot :)
The answer is 10/36 or 27.77%
here’s the working out
The function

describes a parabola with vertex = (5, 3).
The graph of the function is attached.