The area of rhombus ABCD is 72 square units. EC = 8 units and DB = x – 1.

What is the value of x?

9
10
14
16

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)