2. Sally charges $8.50 an hour to babysit for the first hour and $7.50 an hour each additional hour. Write an expression to represent the cost Sally charges if x is the number of hours after the first hour.

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.

4hours and 40 mins she would be 120 meters high