5. A circle has an equation of x-4x+ y +8y=149. (a) Show that the point (7, 8) must lie on this (b) Determine the center and radius of this circle. circle. (d) There are two points on this circle at which the slope of the tangent line is undefined. What are they? Explain your answer. (c) Determine the equation of the tangent to the circle at (7,8). Show how you arrived at your answer.