Answer:
a. 

b. 

c. 

d. 

Explanation:
When multiplying or dividing numbers with exponents, the rule is that you add the exponents together if multiplying, or subtract them if dividing. This is only possible with numbers of the same base (the number before the exponent).
 multiplied by
 multiplied by 
 is
 is 
 because the exponents, 2 and 2, are added together. The bases remain unchanged.
 because the exponents, 2 and 2, are added together. The bases remain unchanged.
 times
 times 
 is
 is 
 because another way to write
 because another way to write 
 is
 is 
 , and the exponents can be added together from there.
, and the exponents can be added together from there.
The same logic can be applied to the division questions, but with subtraction instead of addition.