How would you multiply fractions to whole numbers?

Are carpet coast $15 per square metre. the total delivery charge is $21 peter buys n squared metres of carpet what is the expression which represents the total cost in $

Divide the following fractions 3/4 ÷ 2/3 1/2 8/9 9/8 2

Terri makes a quilt using three sizes of fabric squares the side lenght of each fabric square is the square root of the area