9. add 19.
p + 19 = s
input output

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.

80x^8−68x^6+16^5−20x^4−4x^3+8x^2

hope i'm right lol