Jenny is renting a moving truck. She will have to pay a one-time fee for insurance coverage and pay the daily rate for the truck each day she used it. The total cost of renting the truck
in terms of the number of days the move will take can be modeled by the following
function: d(x) = 110x + 85. If She paid a total of $525 at the end of her rental, for how
many days had she rented the truck?

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: