Answer:

Step-by-step explanation:
Given


Required
The cost of units used
First, calculate the number of units used.



Next, multiply the units used by the cost per units,
Since the cost per unit is not given, we assume that it is x.
So, the total cost is:



Isolate z by itself:

To simplify variables with powers, subtract the smaller power from the bigger power:


The exponent will be
-3.
Answer:
it's 12
Step-by-step explanation:
2 and 2/5 divide by 1/5 is 12
Answer:
0.56457
Step-by-step explanation:
log 3 with base 7 = (Log 3)/ (Log 7) = 0.47712125 / 0.845098040014
(Log 3) / (Log 7) = 0.56457