Answer:
16
Explanation:
We are given
.
If we square both sides we obtain
.
Recall
.
So we have
.
Reorder this so we can use the second given:
.


Subtract 8 on both sides:

Divide both sides by 2:

So we have the following so far:



We are asked to find
.
We will now cube both sides of the first given:


Expand left hand side:

Factor and reorder:

Plug in values given and the value we found for
:

Simplify third term of left hand side:

Subtract 48 on both sides:
