Determine the requested value . please help me work out these problems

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.

8,400-6,400=xx/6,400anyways the percent increase is 31.25% or 0.3125 you can round if you can