Ineed this is a top question

When you raise a negative integer (in this case -1) to an even integer (30), the end result will be positive (1), but when you raise it to an odd integer (31), the end result will be negative (-1). The sign of the product fluctuates between positive and negative depending on the type of integer it’s raised to.

First step is to get rid of the square root. remember that a square root is the same as raising to the (1/2) power. see below: multiply exponents per exponent rules to get: remember you subtract exponents from the denominator and add exponents in the numerator so: simplify further: so a is the correct choice. if you don't understand this google exponent rules and it will you understand. look at the image results.