1. The following are examples of polynomials, EXCEPT a. x2 - 4x + 5
c. 3x4 -5x + 2x - 1
b. 4x3 + 8x2 + 10x - 7
d.x- y

Try d if it does happen to be wrong I am so sorry!

Step-by-step explanation:

21 1/2 is 43/2 you divide that by 1/4 which when you divide by a fraction you flip the fraction and instead of dividing you multiply so 43/2 × 4 is 172/2=86. * in the picture the process at multiplication is not the same as what I wrote but it is still done and solved correctly so you can choose the process you prefer