1) x/2 stilou ; x-x/2 =x/2 ramas
2) 1/3*x/2 =x/6 carioci ; x/2-x/6 =3x/6-x/6 =2x/6 =x/3 ramas
3) 1/4 *x/3 =x/12 caiet
4) 12 lei / carte
x/2+x/6+x/12+12 =x numitor 12
6x+2x+x+144=12x
12x-6x-2x-x =144
3x =144
x =48
1) x/2 =48/2 =24 lei/ stilou
2) x/6 =48/6 =8 lei carioci
3) x/12 =48/12 =4 lei / caiet
4) 12lei / carte