Răspuns :
x-x/10-(x-x/10)*1/10=810
x-x/10-1/10(x-x/10)=810
x-x/10-x/10+x/100=810
x-x/5+x/100=810
100x-20x+x=81000
81x=81000
x=1000(lei)
x-x/10-1/10(x-x/10)=810
x-x/10-x/10+x/100=810
x-x/5+x/100=810
100x-20x+x=81000
81x=81000
x=1000(lei)