1. The distance between the points (x,21) and (4,7) is 10sqrt2 Find the sum of all possible values of x.
+128475 Let's just get the square of the distance formula
Note 10sqrt (2) = sqrt (200)
( 4 - x)^2 + (21 - 7)^2 = (sqrt 200)^2 expand and simplify
(x - 4)^2 + 14^2 = 200
(x - 4)^2 + 196 = 200
(x - 4)^2 = 4 take both roots
x - 4 = sqrt (4) and x - 4 = -sqrt (4)
x - 4 = 2 x - 4 = -2
x = 6 x = 2
So...the sum = 6 + 2 = 8
