Element X is a radioactive isotope such that every 28 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 40 grams, how much of the element would remain after 11 years, to the nearest whole number?

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:

(-1,-0.5)

step-by-step explanation:

sadsadsadsad

step-by-step explanation:

r = 78539458390583095803458309458039485093485 or just 3

step-by-step explanation: