Bună!
x=prețul inițial
scumpirea 1 → x+10%×x
scumpirea 2 → (x+10%×x)+10%×(x+10%×x)
preț final=13,31
(x+10%×x)+10%×(x+10%×x)=13,31 ⇔
(dăm factor comun) ⇔ (1+10%)×(x+10%×x)=13, 31 ⇔
⇔ [tex](^{10)} 1+\frac{10}{100} )*(^{10)} x+\frac{10}{100} *x)=13,31[/tex] ⇔
⇔ [tex]\frac{11}{10} *\frac{11x}{10} =13,31[/tex] ⇔
⇔ [tex]\frac{121x}{100} =13,31[/tex] ⇒ [tex]x=\frac{100}{121} *\frac{1331}{100}[/tex] ⇒ [tex]x=11[/tex]
