Hello, I with this problem, I am getting the correct answer, but I do not know why the book's answer is negative: "Consider the following mass distribution: 5.00 kg at (0,0) m, 3.00 kg at (0, 4.00) m, and 4.00 kg at (3.00, 0) m. Where should a fourth object of mass 8.00 kg be placed so that the center of gravity of the four-object arrangement will be at (0,0)?" I understand that the center of gravity is the sum of the masses multiplied by the x and y coordinates divided by the sum of the masses of the objects. The answer I come to are (1.5, 1.5). The book says both of those coordinates are negative. What did I do wrong? Thank you.