The midpoint of a line segment PQ is M(3, −1). If P has coordinates (7, 4), find the coordinates of Q.

Using the midpoint formula: M = ((x₁+x₂)/2, (y₁+y₂)/2). So (7+x₂)/2 = 3 gives x₂ = −1, and (4+y₂)/2 = −1 gives y₂ = −6. Therefore Q = (−1, −6). Option C doubles the midpoint coordinates instead of solving correctly, and option D has the correct x but wrong sign for y.