What are the domain and range of the function below. •(-2, infinity) •(-2,4] and [7, infinity) •(-infinity,4) [-2,0] and (7,infinity)

What mathematical statement is missing ? ? the answer is b

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.