A rectangular building with a square front is to be constructed of materials that costs 12 dollars per ft2 for the flat roof, 18 dollars per ft2 for the sides and the back, and 20 dollars per ft2 for the glass front. We will ignore the bottom of the building. If the volume of the building is 5,600 ft3, what dimensions will minimize the cost of materials?

Element 17 is chlorine it is a group 7 element(halogen) and belongs to period 3 of the periodic table

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.