Respuesta :
so she saved $20 and that was 40% of the regular price, let's say the regular price is "x".
if 20 is 40%, what is "x" or namely the 100%?
[tex]\bf \begin{array}{ccll} amount0&\%\\ \cline{1-2} 20&40\\ x&100 \end{array}\implies \cfrac{20}{x}=\cfrac{40}{100}\implies \cfrac{20}{x}=\cfrac{2}{5}\implies 100=2x \\\\\\ \cfrac{100}{2}=x\implies 50=x[/tex]
