The length of the segment between the points (2a, a-4) and (4, -1) is \(2\sqrt{10}\)units. What is the product of all possible values for a?
Try substituting all of this into the distance formula first and expand. See where you can go from there.
USe distance formula
(2a-4)^2 + (a-4 - -1)^2 = (2 sqrt10)^2
4a^2 - 16a + 16 + a^2 -6a +9 = 40
5a^2 - 22a -15 = 0 quadratic formula shows a = 5 or - 0.6 you can take it from here