Sue charges $15 per hour for the first hour of babysitting and $10 for each additional hour, with each fraction of an hour counted as a whole hour. The rates that Vic charges for x hours are modeled by the function shown. Part B - What is the rate of change for each function over the interval 7 ≤ x ≤ 11? *

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.