I'm assuming this is multiple choice and you forgot to post the answers. I'll take a guess and say it probably looks something like this:

Because you can't take the square root of a negative number without getting an imaginary result, resulting in the function having a closed domain limit.
Answer: 
Step-by-step explanation:
Assuming the described expression is:

And knowing the condition
and 
We cansimplify it following the rules related to the exponents with the same base:

Finally:

Answer: x=4,y=5
Step-by-step explanation:
The answer is b because no x-value can repeat.
Answer:
The least possible number of coins that Pirate Jack has is 77.
Step-by-step explanation:
i) let the number of coins in the piles for the parrots be x.
ii) therefore we can say that the total number of coins be 7x + 4
iii) let the number of coins in the piles for for the pirates be y.
iv) therefore we can say that the total number of coins be 11y + 4
v) therefore we can say that 7x + 4 = 11y + 4
vi) therefore 7x = 11y
vii) therefore the least possible number of coins that Pirate Jack has is equal to the LCM of 11 and 7 which is 77.
viii) x = 11 and y = 7