Question

Dupa ce a citit 2pe 3 dintr-o carte,Elenei i-au mai ramas de citit 50 de pagini.Cate pagini are cartea?

Answer 1

$x-\frac{2}{3}*x=50 \\ \frac{x}{1}-\frac{x*2}{3}=50 \\ \frac{x*3}{3}-\frac{2x}{3}=50 \\ \frac{3x}{3}-\frac{2x}{3}=50 \\ \frac{3x-2x}{3}=50 \\ \frac{x}{3}=50 \\ x=50*3 \\ x=150 \\ Raspuns:150.pagini \\ Sfrarsit!$