Identify the variable expression that is not a polynomial

The number of pages in the u.s. tax code exceeds the number of pages in the king james bible by 18,528. the combined number of pages in the tax code and the bible is 21,472

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

Kendra had twice as much money as kareem. kendra later spent $8 and kareem earned $6. by then,the two had the same amount of money. how much money did each have originally?