Given the formula, solve for the indicated variable.
f=9/5c + 32 for c

F = c + 32   Subtract 32 from both sides
F - 32 = c   Mutliply both sides by  to cancel out the fraction
F - 17  = c   Switch the sides to make it easier to read
c = F - 17  

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.