Parallelogram JKLM is shown on the coordinate plane below:If parallelogram JKLM is rotated 270° clockwise around the origin, what are the coordinates of the endpoints of the side congruent to side JM in the image parallelogram?

Given that rotating 90 degrees clockwise around the origin switches the x andy values and makes the new y value negative, we can, for example, switch (2, 1) to (1, -2). 180 degrees clockwise simply makes both values negative (-2, -1), and 270 degrees clockwise switches them and makes the new y value negative  (-1, 2), we can plug those in to our JM endpoints to turn (-5, 1) into (-1, -5) and (-6, 2) into (-2, -6)