Puzzle a Day!

JJB
Square the first number to get the number inside the brackets, reverse that number and divide by the first digit of the original bracketed number to get the number to the right of the bracket.

Like I said somewhere, I think the first step (squaring) was a red herring. It would have made more sense if the last part of the question was 64 (????) ? .

Ahhhhh never tried reversing the bracketed number, it's all so obvious now!