At noon the horse and buggy headed north at 10 miles per hour. Two hours later, the roadster headed south from the same location at 20 miles per hour. At what time will the horse and buggy be 230 miles from the roadster

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.

If she spent  3/8 playing games and 50% eating, that would be 4/8. so she would have had to spend 1/8 opening presents

It is a trinomial with a degree of 2 i believe