Răspuns :
p - 25%p = 2100
p - 25p/100 = 2100
p - p/4 = 2100
4p - p = 8400
3p = 8400
p = 2800 lei pret initial
100 - 25 = 75 %......2.100 RON
100 %........X RON
X = 100 × 2.100 : 75
X = 210.000 : 75
X = 2.800
100 %........X RON
X = 100 × 2.100 : 75
X = 210.000 : 75
X = 2.800