Which number is not in scientific notation?
a) 9 ⋅ 10 to the power of 19
b) 7.8 ⋅ 10 to the power of 6
c) 1.45 ⋅ 10to the power of −7
d) 0.33 ⋅ 10 to the power −15

for scientific notation you want a whole number multiplied by 10 to a power

 so since D is a decimal ( 0.33) that is not scientific notation

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: