6sqrt2 for both since there equivalent
For this case we have that by definition, a direct variation is given by:

Where:
k: It is the constant of proportionality of the variables.
On the other hand, we have that the inverse variation is given by:

Where:
k: It is the constant of proportionality of the variables.
In this way, the correct option is: 
ANswer:
Option A
Answer: (8a^3x^3)/81
Step-by-step explanation: Simplifying the expression :)
Ax+bx−c=0
Step 1: Add c to both sides.
ax+bx−c+c=0+c
ax+bx=c
Step 2: Factor out variable x.
x(a+b)=c
Step 3: Divide both sides by a+b.
x(a+b)a+b=ca+b
x=ca+b