The equation d = 22.5n + 27.5 represents the amount of money, in dollars, that Kathryn earns for each sale she makes. The variable n represents the number of items sold, and the variable d represents the total amount of money earned. What is the number of items Kathryn must sell in order to earn $500?

Step-by-step explanation:

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation:

29.5977692753

step-by-step explanation: