To solve this problem you must apply the proccedure shown below:
1. You have that
varies jointly as
and
and inversely as the product of
and
. Therefore, you can write the following equation, where
is the constant of proportionality:

2. Now, you must solve for the constant of proportionality, as following:

3. Susbtiute values:


4. Substitute the value of the constant of proportionality into the equation:

The answer is: 
Answer:No Matt's calculation is not correct.
Step-by-step explanation:
We have to multiply by the number of the area.If it is 4 inches we multiply by 4
15 x 4 =60
A=4 inches squared
A=LxW (length x width )
so you can say that:
Matt is incorrect because He skipped the step of multiplying 2 by 2 in the formula which is where we get 4 from.
Answer:
which one 1,2,3,4,5,6,7,8