An element with mass 210 grams decays by 8.3% per minute. how much of the element is remaining after 15 minutes, to the nearest 10th of a gram?

Step-by-step explanation:

In this problem we have a exponential function of the form

where

f(x) is the remaining mass of the element in grams

x is the time in minutes

a is the initial value (y-intercept of the exponential function)

b is the base

r is the rate

In this problem we have

---> is negative because is a decay's rate

substitute

The exponential function is equal to

For x=15 minutes

substitute in the function

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: