Answer: The refrigerator cost in this month is $4.5 approximately.
Step-by-step explanation:
Since we have given that
Amount of watt of electric power = 320 W
Number of days = 30
Unit cost of electricity = $0.13/Kwh
Hold factor = 
Number of hours in a month = 24
So, the refrigerator cost in this month would be

Hence, the refrigerator cost in this month is $4.5 approximately.
Step-by-step explanation:
In simplest radical form
= √-3
= -3^(1/2)
or
= √-3
= √3i
i is imaginary number, you can write it if you find a negative number in a square root
The answer would be c because the absolute value of both numbers would be the distance between them