Take the coefficient of x which is 20 and divide divide by two giving you 10 Now square that to get 100.
You would need to add 100 to both sides to complete the square.
If you're interested in determining which player's game performances show the least variability, you'd want to identify the smallest and largest number of points (minimum and max).
The answer is 81 2/5 or 81.4. You have to change 9 1/4 and 8 4/5 to decimals and then multiply.