Suppose q (1,-9/2)is the midpoint of the line segment ab and suppose a is the point (6,5) find b

Q(x, y) = ((x1 + x2)/2, (y1 + y2)/2)
Q(1, -9/2) = ((6 + x2)/2, (5 + y2)/2)
(6 + x2)/2 = 1
6 + x2 = 1 * 2 = 2
x2 = 2 - 6 = -4

(5 + y2)/2 = -9/2
5 + y2 = -9
y2 = -9 - 5 = -14

Therefore, B = (-4, -14)