Shell gas station is having a sale on diesel. If you buy $\displaystyle {4}$ gallons or less, you pay the regular price of $\displaystyle \${3.89}$ per gallon. If you buy more than $\displaystyle {4}$ gallons, you pay $\displaystyle \${3.59}$ per gallon. Write a piecewise function for the price of $\displaystyle {n}$ gallons of diesel at Shell.

$\displaystyle {D}{\left({n}\right)}={\left\lbrace\begin{array}{c} \\\\\end{array}\right.}$	Preview Question 1 Part 1 of 4	if $\displaystyle {0}<{n}\le$
	Preview Question 1 Part 3 of 4	if $\displaystyle {n}>$