9+9+9+9+9+81+828+8282+92929=

dont use calculator otherwise I will report u

102165

Step-by-step explanation:

92929+8282= 101211

101211 + 828 = 102039

102039 + 81 = 102120

102120 + (9+9+9+9+9) = 102120 + 45 = 102165

102165 is your asnwer

Step-by-step explanation:

9+9+9+9+9+81+828+8282+92929=102165

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:

the surface area is 124cm²

step-by-step explanation:

length: 4cm

width: 9cm

height:   2cm