Mrs. Holloway is teaching a 5th grade class. She is standing 42 feet in front of Alan. Gina is sitting 40 feet to Alan's right. How far apart is Mrs. Holloway and Gina?

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.