### Instruction: Simplify the following expression: $\sqrt{28 + \sqrt{1296}}$.### Response: I notice that 1296 is a perfect square, since it is 36 times 36.
So I can simplify the inner square root as 36.
That gives me $\sqrt{28 + 36}$.
Now I can add 28 and 36 to get 64.
And 64 is also a perfect square, since it is 8 times 8.
So I can simplify the outer square root as 8.
That is my final answer.