Question 1:
For this case we have that by definition, the GCF of two numbers is the largest number that is a factor of both numbers. For example, the number 10 is the biggest factor that 50 and 30 have in common.
We must find the GCF of the following expression:

We look for the prime factorization of each number:

The GCF of the three numbers is 
So:

Answer:
Option C
Question 2:
For this case we have that by definition of power properties of the same base, that:

That is, for multiplication of powers of the same base, the same base is placed and the exponents are added.
So:

ANswer:

Option A