Answer:
Value of y is 1536.
Step-by-step explanation:
We have given an expression 
We need to find the value of y when x=8
We will substitute the value of x as 8 in the given expression we get

On simplification we get

On further simplification we get:

Hence, the required value that is the value of y is 1536
D is the correct answer to this question
So I use the formula hopefully these steps work