To find the number that goes in place of ??? in your expression, we need to calculate the discriminant of the quadratic equation using the formula:
In your equation
Now, substituting these values into the formula:
Calculating each term:
Now, substituting back into the discriminant formula:
So the expression under the square root in the quadratic formula becomes
Thus, the number that goes in place of ??? is 169.
Your equation is now: