I am not sure maybe it is 6
The answer is 196/3 pi in^3. All you have to do is multiply 7x7, then you have to multiply that by 1/3 and 4, and you get 65.333333333. Then, you have to turn it into a fraction. You have to multiply 65 by 3, then add one, and you get 196/3 pi in^3.
For this case we must simplify the following expression:
We eliminate the parentheses taking into account that:

So:

We add similar terms taking into account that:
Equal signs are added and the same sign is placed.
Different signs are subtracted and the major sign is placed.

Answer:

98.66074, you just multiply the two values