One way is that you can just factor it out: (x+2)(x+2)(x+2)
For the first pair, you get

.
Then do

*

That will be

So the answer is 6
Answer:
B.
C.
D.
E.
Step-by-step explanation:

We know that,
- Pythagoras theoram is given by : p² + b² = h²
- In a Pythagoras triplet, the longest side represents the hypotenuse of the triangle.
Then,
We should check that, whether the sum of squares of the smaller sides will be equal to the square of the third side or not. Then, we can determine the above easily.
Sum of squares of smaller sides:
= 6² + 8²
= 36 + 64
= 100
Square of longer side:
= 10²
= 100
Sum of squares of smaller sides = Square of longer side. Hence, 6,8,10 are Pythagorean triplets.
And we are done! :D
⛱️ 
B. (n + 15) x 3--- That seems to be the correct answer. I hope I helped!