How many gallons of water can fill a pool that is 50 yards by 20 yards and is 9 feet deep? (assume 7 1/2 gallons per cubic foot.)

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.