[tex]a)x\to pretul \ initial \\\\ 20\% \ din \ x= \frac{\not20}{\not100} *x = \frac{1}{5}*x \to \frac{x}{5} -prima \ marire \\\\ x^{(5}+ \frac{x}{5}=\frac{5x+x}{5}= \frac{6x}{5}-noul \ pret \\\\ 20\% \ din \frac{6x}{5}= \frac{\not20}{\not100}*\frac{6x}{5}= \frac{1}{5}*\frac{6x}{5}\to \frac{6x}{25}-a \ doua \ marire \\\\ \frac{6x}{5}^{(5}+\frac{6x}{25}=\frac{30x+6x}{25} \to \frac{36x}{25}-noul \ nou \ pret \\\\ \frac{36x}{25}= 432 \\\\ x= \frac{25*432}{36} \\\\ x=25*12 \\\\ \boxed{x=300}[/tex]
[tex]b)p\% \ din \ 432=300 \\\\ \frac{p}{100}*432=300 \\\\ \frac{p}{100}=\frac{300}{432} \\\\ p=\frac{100*\not300}{\not432} \\\\ p=\frac{100*100}{144} \\\\ p=\frac{10000}{144} \\\\ p=\frac{625}{9} \\\\\ \boxed{p=69,4\%}[/tex]
