I think it's A) 20 because 8+12 is 20... But I'm not good at math lol :( sorry if this is wrong
Answer:

Step-by-step explanation:
For a negative exponent you always flip the number so instead of
it would be
and 5 to the first power is 5
Now for
any exponent with a zero it always equals 1
So 
Hope this helps!
Answer:
Hai
Step-by-step explanation:
All cubes are similar because every one of them have an equal width and length and height.
I really hope I helped