Answer:
<em>Student 2 is incorrect because he didn't use the formula properly</em>
Step-by-step explanation:
The exponential function is often used to model natural growing or decaying processes, where the change is proportional to the actual quantity.
An exponential decaying function is expressed as:

Where:
C(t) is the actual value of the function at time t
Co is the initial value of C at t=0
r is the decaying rate, expressed in decimal
The initial value of the item is Co=$1000, the rate of decay is r=40%=0.4, and the time is t=3 years.
Substituting into the formula:


C(3)=$216
Student 2 is incorrect because he didn't use the formula properly
Answer:
Equivalent 
Step-by-step explanation:
Given: 3 radical 8
Mathematically 3 radical 8 can be written as 
We have to find an equivalent to
.
Given expression can be written as ,

On further simplification, we get,

We know 
further simplification gives,

Thus, Equivalent 
Please find the attached image
Answer:
-6
Step-by-step explanation:
You multiply -2 by 3 and you get -6.
2 negatives or 2 positives equals a positive number in Multiplication and Division.
But a Negative number and a positive number equals a negative number in Multiplication and Division.
Answer: the system of equations that represents this situation are
12x + 6y = 180
x = 2y
Step-by-step explanation:
Let x represent the number of hardcover books that were sold in a day.
Let y represent the number of paperback books that were sold in a day.
The discount bookstore sells hardcover books for $12 and paperback books for $6. The total sales that day were $180. It means that
12x + 6y = 180
The number of hardcover books sold that day was twice the number of paperback books. It means that
x = 2y