Finite math please help me

If you are trying to move an attached term across the equal sign (=), what operation would you use to move it?

Sum of the interior angles of a pentagon

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)