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 \(a\)?
Distance between the two points is given by the distance formula
(2a-4)^2 + ((a-4)--1)^2
4a^2 -16a+16 + a^2-6a +9 = (2 sqrt10)^2
5 a^2 -22a + 25 = 40
5a^2-22a - 15 = 0
a = 5 or -3/5 (by Quadratic Formula)
5 * -3/5 = -3
Agree with Tertre....
5a^2-22a - 15 = 0
Use Quadratic Formula (as Tertre posted) a = 5 b = -22 c = -15 to find the possible values of 'a' in the equation