How does the graph below change between point A and point B?

The line is an upside U shape from A to B

This means the graph increases, then decreases.

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.