It is already to late to answer this because my final was due yesterday: What percent is increase if the boy had 12 comic books and bought mores so now he has 15 comic books.

36x2 + 49y2 = 1,764 the foci are located at: (-√13, 0) and (√13,0) (0, -√13) and (0,√13) (-1, 0) and (1, 0)edit: the answer is (- the square root of 13, 0) and (the square root of 13, 0)