Let:
Op = Original price
Dp = Discount price
r = percent of discount
The discount price will be, the original price minus the product of the original price and the percent of discount, so:
[tex]\begin{gathered} Dp=Op-Op\cdot r \\ where \\ Op=175 \\ Dp=99.75 \\ 99.75=175-175\cdot r \\ 175\cdot r=175-99.75 \\ 175\cdot r=75.25 \\ r=\frac{75.25}{175} \\ r=0.43 \end{gathered}[/tex]The percent of discount of the item is 43%