When adding 35.64 to a certain number, the sum is 38.24, as seen below. What number should go in the box to complete the addition problem? a 2
b
3
c
13
d
14

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)