If 9 is subtracted from a certain number and the difference is divided by 3, the result is 1 more than 1/7 of the original number. Find the original number.

Let the number be x.

(x-9)/3= (x/7)+1

(x-9)/3= (x+7)/7

Cross multiplying

7x-63= 3x+21

4x= 84

x= 42

Hope this will help :-)

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: