A rectangular visiting card is to contain $24 \text{ sq.cm.}$ of printed matter. The margins at the top and bottom of the card are to be $1 \text{ cm}$ and the margins on the left and right are to be $1\frac{1}{2} \text{ cm}$ as shown below : On the basis of the above information, answer the following questions : (i) Write the expression for the area of the visiting card in terms of $x$. (ii) Obtain the dimensions of the card of minimum area.