Find X such that the point (X, 8) is 13 units from (7, -4)

Answer 1

√((x-7)^2 + 12^2) = 13
square both sides and expand
x^2 - 14x + 49 + 144 = 169
x^2 - 14x +24 = 0
(x-12)(x-2) = 0
x = 12 or x = 2