The bill for the repair of your refrigerator was $146. The cost for parts was $74. The cost for the service call and the first half hour of service was $50. The additional cost for labor was $22 per half hour. How many hours did the repair work take?

146 - 74= 72

72 - 50 = 22

from the $50 is 30 mins of work

add on another 30 mins for the $22

it took 1 hr

i really dont know

step-by-step explanation:

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: