Question 980247
If (-10,-2), (-3,4), and (6,4) are coordinates of three vertices (corners) of a parallelogram, determine the coordinates of three different points that could serve as the fourth vertex.

My answer was (-1,-2), (-20,-2), and (-13,4). The books answer was (-1,-2), (-19,-2), and (13,10). I drew the graph with my three points and it has the shape of the parallelogram.
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(-13,4) doesn't work
(-20,-2) is close, 1 unit off is all.