Question 387399
substituting ___ x^2 + (2x - 10)^2 - 4x + 2(2x - 10) = 0


x^2 + 4x^2 - 40x + 100 - 4x + 4x - 20 = 0


5x^2 - 40x + 80 = 0


x^2 - 8x + 16 = 0


(x - 4)^2 = 0


x = 4


y = 2(4) - 10 = -2


since there is only one solution for x , there is only one point of contact between the line and the circle
this defines the tangent


the point of tangency is (4,-2)