Răspuns :
Notam cu x pretul obiectului :
x - 10x /100 = x -5
100x - 10x = 100x - 500
90x = 100x - 500
500 = 100x - 90x
500 = 10x
x = 500 / 10
x = 50 lei
x - 10x /100 = x -5
100x - 10x = 100x - 500
90x = 100x - 500
500 = 100x - 90x
500 = 10x
x = 500 / 10
x = 50 lei