Step-by-step explanation:
We need to solve where p is the price.
Dividing both sides by 0.80
[tex]\frac{0.80p}{0.80}=\frac{320}{0.80}\\\\p=\frac{320\times 100}{0.080\times 100}\\\\p=\frac{320\times 100}{80}\\\\p=\frac{4\times 80\times 100}{80}\\\\p=4\times 100\\\\p=400[/tex]
Original price is 400