is 12.5 ok I think ,......................,,,,,,
5/9 because you have to add those two together and put that number over the total number of marbles.
The area of rectangle with length l and width w is
If the length of rectangle is expressed as 
and the width of rectangle is expressed as 
, then the area of rectangle is
X^4 - 5x^2 - 36 = 0
(x^2 - 9)(x^2 + 4) = 0
(x-3)(x+3)(x-2)(x+2) = 0
x = -3, -2, 2, 3
