The distance between the points (x, 21) and (7,4) is 20√2. Find the sum of all possible values of x.
+37146 Use distance formula
d^2 = 800
800 = ( x-7)^2 + ( 21-4)^2
800 = x^2 -14x+49 + 289
x^2 - 14x -462 = 0 <======= Now use Quadratic Formula to solve for 'x'
