Answer:
[tex]\$498.75[/tex]
Step-by-step explanation:
Let [tex]x[/tex] be the original price of the item. We can set up the following equation:
[tex]x\cdot (1-0.2)=399[/tex].
Solving for [tex]x[/tex], we get:
[tex]x\cdot 0.8=399,\\x=\frac{399}{0.8},\\x=\fbox{$\$498.75$}[/tex].