If | ab | = 8, then the equation of line L is () A. 5x + 12Y + 20 = 0b. 5x-2y + 20 = 0C. 5x + 12Y + 20 = 0 or x + 4 = 0d. 5x-2y + 20 = 0 or x + 4 = 0

If | ab | = 8, then the equation of line L is () A. 5x + 12Y + 20 = 0b. 5x-2y + 20 = 0C. 5x + 12Y + 20 = 0 or x + 4 = 0d. 5x-2y + 20 = 0 or x + 4 = 0

From the circle x2 + Y2 + 2x-4y-20 = 0, the standard equation is (x + 1) 2 + (Y-2) 2 = 25. The center of the circle m (- 1,2), radius 5, chord length | ab | = 8, and the distance from the center of the circle to the line L D = 52 − 42 = 3. When the slope of the line passing through the point (- 4,0) does not exist, the linear equation is x + 4 = 0, which satisfies the condition; when the slope exists, let the linear equation be y = K (x + 4), that is KX -Y + 4K = 0. The distance from the center of the circle to the straight line d = | - K − 2 + 4K | K2 + 1 = 3. The solution is k = - 512. The equation of the straight line L is − 512x − y + 4 × (− 512) = 0, that is, 5x + 12Y + 20 = 0. To sum up, the linear equation obtained is 5x + 12Y + 20 = 0 or x + 4 = 0