And elementary school collected 1705 bottles for recycling program high school also collected some bottles both schools collected 3627 bottles combined but how many bottles did the high school collect?

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.