Alandscape architect wished to enclose a rectangular garden on one side by a brick wall costing $20/ft and on the other three sides by a metal fence costing $10/ft. if the area of the garden is 22 square feet, find the dimensions of the garden that minimize the cost.

To minimize the cost, you would want the side with the brick wall to be as small as possible. as you provided no restraints to the size, a garden which is 1 foot wide by 22 feet long would be most cost effective, with 22 feet times 2 sides equaling 44 feet in total, plus one foot for the back wall. With a total of 45 feet of fence costing $450, and 1 foot of brick which will cost $20, the total cost would be $470.

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.