What must be given to prove that δcjg ~ δcea?

We need a picture in order to understand your problem. I have the same problem but that doesn't mean that everything is in the same order. Understand?

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.