Answer:
For the case when x = 8, we have that y = 2/3.
Explanation:
The idea that y varies directly as x, can be written in an equation as:
y = k*x, where k is an unknown constant (until now).
We know that y=6 when x=72, then, substituting these values in the above formula gives us the value of k:
6 = k*72, then: k = 6/72 = 1/12.
Now, we can rewrite our initial expression with the known value of k as:
y = (1/12)*x
For the case when x = 8, we have that:
y = (1/12)*8 = 8/12 = 2/3.