Suppose you deposited $200 in a savings account 2 years ago. The simple interest rate is 3.2%. The interest that you earned in those 2 years is $12.80. Which of the following is/are true?
p=200
r= 12.80 t=2
I= 3.2%

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.