Sasha had 30 dollars to spend on 3 gifts. She spent 10 9/10 dollars on gift A and 5 3/5 dollars on gift B. How much money did she have left for gift C?

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.