x*1/2=x/2 pt caiet
x-x/2=2x/2-x/2=x/2 x/2*1/3=x/6 pt stilou
x/2+x/6=3x/6+x/6=4x/6=2x/3
x-2x/3=3x/3-2x/3=x/3 x/3*1/4=x/12 pt creioane
x/2+x/6+x/12+12=x
6x+2x+x-12x=-144
-3x=-144
x=48 lei a avut initial
x/2=48/2=24 lei pt caiet
x/6=48/6=8 lei pt stilou
x/12=48/12=4 lei pt creioane
24+8+4+12=48 proba