Given the functions f(n) = 11 and g(n) = -2(n - 1), combine them to create an arithmetic sequence, an, and solve for the 31st term.

an = 11 - 2(n - 1); a31 = -49
an = 11 - 2(n - 1); a31 = -51
an = 11 + 2(n - 1); a31 = 71
an = 11 + 2(n - 1); a31 = 73

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: