Two friends who live 48 miles apart, left their houses at the same time and started to run towards each other at the rates of 5 mph and 7 mph. how much closer to each other will they be in one hour? how soon will they meet?

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.