Bobby bikes 3 miles to the store and 3 miles back, The wind is blowing in his face 4 miles per hour going and 4 miles per hour pushing him home. The trip takes him 1 hour. How long would it take Bobby to bike 2 miles if no wind is blowing?

What's the denominator

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.