1.
x=distanta
35%x=35x/100=7x/20=ziua 1
x-7x/20=13x/20=rest
13x/20 × 80%=13x/20 × 80/100=13x/20 × 4/5=13x/25=ziua 2
7x/20+13x/25+260=x
35x+52x+26000=100x
13x=26000
x=2000 km
2. 100%-10%=90%
99:90%=99 :90/100=99 × 100/90 = 110 lei inainte de ieftinire
100%+10%=110%
110 :110%=110 :110/100=110 × 100/110 = 100 lei pret initial