Mackenzie has one candy bar to share equally with her best friend. What portion of the candy bar does Mackenzie give to her best friend.

1/2

Step-by-step explanation: if each of you get part of the candy bar and you need to share it equally, both of you get 1/2 of it.

the function makes a strait line horizontally with no x intercept but a y intercept at 9.

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.