Find x so the distance between (x,4) and (1,8) is 2 square root of 5.

Question

Find x so the distance between  and  is .

Answer 1

d^2 = (2sqr5)^2 = 4(5) = 20 = (x-1)^2 + 4^2

(x-1)^2 = 20-16 = 4

x-1 = + or - 2

x = -1 or 3