knight247 wrote:OA is D

I solved it in this manner... Point F with co-ordinates 2,-1 is the midpoint of two points... i.e.

x1+x2/2=2 or **x1+x2=4** and y1+y2/2=-1 or **y1+y2=-2**. I then checked which answer choices meet this requirement. I narrowed it down to B and D. But am unable to go any further. Hoping to get some detailed explanations. Cheers.

ALWAYS LOOK AT THE ANSWER CHOICES.

Since B and D include the same two coordinate pairs, just in reverse order, the ordering in the answer choices must reflect the ordering in the question: the first coordinate pair in each answer choice is B, the second A.

Since the x coordinate of F is 2, the x coordinate of B must be greater than 2, and the x coordinate of A must be less than 2.

Only answer choice

D works: (6,-3) and (-2,1).

The correct answer is

D.