It took Lorinda 45 minutes to drive from her house to the airport. It took her 10 minutes to find a parking space and 25 minutes to walk to the terminal and check in. Then it took her 20 minutes to walk to the gate and board the plane. She boarded the plane at 11:10 A. M. At what time did Lorinda leave her house?

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.