Let us call the original price x, shall we?
We are told that after the 20% off on x, the price is $199. Therefore, we can write this situation as
[tex]x-\frac{20}{100}x=199[/tex]Simplifying this gives
[tex]\frac{80}{100}x=199\text{.}[/tex]Alternatively, we could say that after 20% of on x, the sale price is now 80% of the original price. In which case, we have the equation
[tex]\frac{80}{100}x=199.[/tex]which is the same equation as we got first.
Now we need to solve for x. We do this by multiplying both sides by 100 and then dividing by 80:
[tex]100\times\frac{80}{100}x=199\times100[/tex][tex]\Rightarrow80x=19900[/tex]and dividing by 80:
[tex]\frac{80x}{80}=\frac{19900}{80}[/tex][tex]\Rightarrow x=248.75[/tex]Hence, the original price is $248.75.