Look at the numbers in the bon 5
9
-11
6
-21
9
-6
-10
20
1
Find four numbers whose sum is 5

step-by-step explanation: you take each of the numbers and divide by the amount then you take the range

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.