Nixon estimates it will take him 5 hours to finish an art project. it actually take him 320% of the time estimated . how many hours did it take him to finish the project ?

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.

Re-do the question and enter the picture