For question b, how is the answer is ㏒ₐ2 + 4(n-1)㏒ₐ3?
Please help me.

Step-by-step explanation:

nth term of an A.P. is given by the explicit formula,

Here, 'a' = First term

n = number of term

d = common difference

For an A.P. given as,

First term 'a' of the given A.P. =

Common difference 'd' =

                                       =

                                       =

                                       =

                                       =

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:

answer: it's d

step-by-step explanation: