Question

Dupa 2 reduceri consecutive de pret ambele de 10 % un calculator costa 972 lei.care era pretul initial al calculatorului?

Answer 1

[tex]x=pretul\ initial\\ x-\frac{10}{100}x-\frac{10}{100}(x-\frac{10}{100}x)=972\\ x-\frac{x}{10}-\frac{1}{10}(x-\frac{x}{10})=972\\ \frac{9x}{10}-\frac{1}{10}*\frac{9x}{10}=972\\ \frac{9x}{10}-\frac{9x}{100}=972\\ 90x-9x=97200\\ 81x=97200=\ \textgreater \ x=1200 lei[/tex]