Can some answer this solution?

To solve for "b", you need to isolate/get the variable "b" by itself in the equation:

   First multiply 2 on both sides to get rid of the fraction

4b + 8 = 20        Subtract 8 on both sides

4b + 8 - 8 = 20 - 8

4b = 12       Divide 4 on both sides to get "b" by itself

b = 3           [answers are bolded]

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: