Question 122056
Here, let {{{OP}}} be the original price, let {{{D}}} be the discounted price, and {{{p = (x/100)*OP}}} ….(the percentage. "Percent" means "per 100" ; 75% really means 75/100)

Set up the equation 

{{{ D = (x/100)*O }}}

{{{OP = D /(x/100) }}}

Example :

{{{D= 30 }}}
 {{{x = 25}}}
then
${{{ 30  = (25/100)*OP }}}

{{{OP = 30/(25/100) }}}

{{{OP = 30/(0.25) }}}

{{{OP = 120}}}$