<p>am I mistaken, or could that answer have been B or C? Both come out as the answer, 0, but it was marked as wrong. Anyone else get this? This would have made a great difference in my score---from 68 to 71. If I'm right, how do I appeal this? Now I'm gonna check all the other questions! lol</p>
<p>no i'm sorry you are mistaken as x=-y is only one solution.
x^2 = y^2 accounts for the fact that x could equal y and x could equal x=-y.
Thus, this question asks for the most true all the time.
Thus c, accounts for two cases; btw this is what the retarded collegeboard does to us. </p>
<p>I DISLIKE THE PSAT/SAT/ETS/COLLEGEBOARD/TESTS IN GENERAL</p>