Find the value of ccc such that the line x+2y=cx + 2y = cx+2y=c is tangent to the circle x2+y2=5x^2 + y^2 = 5x2+y2=5.
±5\pm \sqrt{5}±5
±5\pm 5±5
±25\pm 2\sqrt{5}±25
±35\pm 3\sqrt{5}±35