Jonathan’s lunch account began with $50 and he spends $2.30 per day on his lunch. Nelson’s lunch account began with $12 and he spends $0.40 per day on his lunch.

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.

It is 6% because if you subtract 69-58=6 so 6% is the answer to your question.