Help please

Adozen bananas weigh 3 pounds how many ounces does 1 banana weigh

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15

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)