What does -(-f) stand for in math. it can be any variable but what does it mean?

J= r + 9 because since jessica rode 9 more miles than roger, you add 9 miles to rogers mileage.

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.

Ibelieve the answer is c i worked it out three times but if my answer is wrong someone correct me