Why is the identity element of multiplication so important in fractions

Handsome jack is buying a pony made of diamonds. the price of the pony is p dollars, and jack also has to pay a 25% diamond pony tax. which of the following expressions could represent how much jack pays in total for the pony?

Y= a(x-3)squared-1 what is the value of a

What are the domain and range of the function below? a) domain: (-4,0) range: [-2,infinity) b) domain: (-3,0) range: [-2,infinity) c) domain: (-infinity, infinity) range: [-2, infinity) d) domain: [-2,infinity) range: (-infinity, infinity)