Jack needed new pencils for school today. He took 6 pencils from a new box of pencils. If there are 18 pencils left in the box, how many pencils were in the brand new box?

24 pencils

Step-by-step explanation:

18+6=24

24 pencils

Step-by-step explanation:

Add the pencils you took out and the pencils left in the box. 6+18=24

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:

both equations and proportions are better.