[tex]x-the \ price \\ \\ 16 \% \ of \ x= \frac{16}{100}*x= \frac{4}{25}* x =\frac{4x}{25}-\ the \ discount \\ \\ x^{(25}-\frac{4x}{25}=\frac{25x-4x}{25}=\frac{21x}{25}- \ the \ new \ price \\ \\ \frac{21x}{25}=18 \\ \\ x=\frac{25*18}{21} =\frac{450}{21} \\ \\ \boxed{x=21.42 \$}[/tex]
