Question

La un magazin are loc o reducere de preturi de 20%. Un tricou costa dupa reducere 46 lei. Ce pret avea tricoul inainte de reducere ?

Answer 1

Se noteaza cu y ce pret avea tricoul inainte de reducere.
y-y·$\frac{20}{100}$=46
⇒$\frac{y}{1}$-y·$\frac{2}{10}$=46
⇒$\frac{10y}{10}$-$\frac{2y}{10}$=46
⇒$\frac{10y-2y}{10}$=46
⇒$\frac{8y}{10}$=46
⇒8y=46·10
⇒8y=460
⇒y=57,5
⇒tricoul a costat 57,5 lei