Răspuns :
125..........100-15= 85%
x........................100%
x= 125*100/85=147,05
x=12500/ 85= 2500/17 ( daca simplifici cu 5)
avem x - (15/100)*x = 125 | *100
100x - 15x = 12500
85x = 12500
x = 12500 / 85 = 2500 / 17 ≈ 147, 06