Which is more economical: purchasing the economy size of a detergent at 2 kilograms for $3.15 or purchasing the regular size at 890 grams for 60cents?

Economy size of detergent; 2 kg of detergent cost 3.15=> 1 kg  

Costs (3.15/2)

Since 1 kg= 1000 g and 1$=100 cents we have  

1000 g of detergent costs ( 3.15/2)*100 cents or  

1 g of detergent costs ( 3.15/2)*100/1000

=3.15/20 cents

Regular size detergent 890 g for 60 thus 1 g costs 60/890 cents  

Lets compare 3.15/20 and 60/890

2/43> 3.15/2

The regular size of detergent  is more economical

15

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: